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View Full Version : How to Mix non-Yellow, High Value, High Chroma Green?


SamL
02-16-2015, 04:21 AM
I tried the "Cobalt Blue + Cadmium Yellow" recipe. I started with Cadmium Yellow. I added Cobalt Blue little by little, until the value was what I wanted. But the result is pure yellow, and not green at all. RGB=(217, 217, 61).

How do you mix high value (light), high chroma green?

For example, the follwing green has RGB=(128, 211, 0), very green, very light, very high chroma (blue=0). How do you mix something like this, and not looking largely yellow?

If I stick with the "Cobalt Blue + Cadmium Yellow" recipe, I guess I can add enough Cobalt Blue to make it true green. But it will be dark. Then I will need to add a lot of white to make it light. Then the result will be a grayish, low chroma, high value green. That is not what I am trying to achieve here.

Patrick1
02-16-2015, 04:46 AM
For reflective surfaces (paints), each hue intrinsically has a relative value when at maximum saturation. We all know violets at maximum saturation are dark while yellows are very light (under the same illumination). Once you're got your green at maximum saturation, the only way to lighten it more is my applying it more dilutely over a white surface, or adding white - both of which will lower the saturation. Or...you can make it yellower...which you don't seem to want.

The highest chroma middle or slightly yellowish green is obtained by PG36 (Phthalo Green Yellow Shade) by itself OR PG36 + just enough Cadmium Lemon or PY3 to shift the hue towards yellow only if needed. Applied at the right thin-ness over a bright white smooth surface. If you need more opacity, you'll need to add white, but this will lose saturation. A lot of bright green convenience mixtures are PG7 or PG36 + PY3 + T. White to opacify.

Gigalot
02-16-2015, 05:24 AM
You need real "Lemon yellow" paint and Phthalo Green. Try Cadmium Yellow lemon or PY3 or, even PY32. Add a tiny amount of Phthalo green to it and see what happens.
Some Brands are making this mixture, mostly PG36+PY3, because it is extremely vivid convenience mixture. Neon green color.

SamL
02-16-2015, 06:47 AM
The attached image is pure green. RGB = (0, 255, 0).

Can this color (or something close to it) be reproduced on canvas with paints?

Gigalot
02-16-2015, 07:09 AM
The attached image is pure green. RGB = (0, 255, 0).

Can this color (or something close to it) be reproduced on canvas with paints?
No, it can't. Take this color into Photoshop and convert it to a CMY mode. You will see the maximum possible saturated green, which can be mixed using real pigments. Try to use it on the black background and you will see maximum neon glow, which can be reached with green on black using real paints. If you need more, improve illumination, use twice or or more powerful light fixture. Sun shine gives approximately one kilowatt of light power energy per square meter. Use 1000 watt halogen projector and you will have real glow!

Your color in CMY:

SamL
02-16-2015, 08:10 AM
No, it can't. Take this color into Photoshop and convert it to a CMY mode. You will see the maximum possible saturated green, which can be mixed using real pigments.
When you say "real pigments", do you mean "3 real pigments - cyan, yellow, and magenta"?

Or do you mean "all real pigments in the world (there may be thousands of them) - from rocks, plants, and chemical factories"?

Mythrill
02-16-2015, 08:29 AM
The attached image is pure green. RGB = (0, 255, 0).

Can this color (or something close to it) be reproduced on canvas with paints?

Sam, if you want the highest-chroma neon green, try Cobalt Turquoise (PG 50) + Lemon Yellow (PY 3). It won't be exactly like the green in this monitor, but it will be so bright it will make your eyes ache.

Gigalot
02-16-2015, 08:38 AM
When you say "real pigments", do you mean "3 real pigments - cyan, yellow, and magenta"?

Or do you mean "all real pigments in the world (there may be thousands of them) - from rocks, plants, and chemical factories"?
I mean Cyan, Yellow and Magenta process ink, but real artist's paints are close to these colors, they also are made from Phthalo Blue, Quin Magenta and Hansa or Diarylide yellow. But you can mix a bit better color, than Cyan+Yellow in CMY process, using pure green pigment and Lemon yellow. You can travel to a supermarket to see there detergent powder packages - sure you will see the most saturated color, which our modern chemistry ever produce! The most bright green among Pantone plate ink colors! :) ;)

Bradicus
02-16-2015, 12:49 PM
I'll ask a related question.
As Cad Red does not mix both ways very good compared to, say, Napthol Red.
Would that be true for Cad Yellow? Not being the ideal mixer, to the green side.
If true(I dont know), then a PY 3 or py184,154, or128 might be the better pick for bright green..

Mythrill, pg50 over pg36 for brightness with py3? I dont have cobalt turq., but pg36 is bright...

Cheers,
Brad

Gigalot
02-16-2015, 01:21 PM
I'll ask a related question.
As Cad Red does not mix both ways very good compared to, say, Napthol Red.
Would that be true for Cad Yellow? Not being the ideal mixer, to the green side.
If true(I dont know), then a PY 3 or py184,154, or128 might be the better pick for bright green..

Mythrill, pg50 over pg36 for brightness with py3? I dont have cobalt turq., but pg36 is bright...

Cheers,
Brad
Cad yellow lemon is ideal to mix green, it reflects whole green light from spectrum. But Cad yellow medium and especially Cad yellow deep mix more dull greens. They can be better to mix orange.
I never tried PG36 and PG50. I don't know, which one is more vivid. I have PG19 and PG7. From this two colors, PG7 is more chromatic.

SamL
02-16-2015, 01:31 PM
But you can mix a bit better color, than Cyan+Yellow in CMY process, using pure green pigment and Lemon yellow
What are the names of those "pure green pigments"?

Gigalot
02-16-2015, 01:56 PM
What are the names of those "pure green pigments"?
PG7 and PG36, Phthalo Green and Phthalo Emerald are more vivid in green mixing than Phthalo Blue GS PB15:3 widely in use as a "Process Cyan" ink.

SamL
02-17-2015, 06:41 PM
Sherwin-Williams has this "SW 6921 Electric Lime Interior / Exterior" paint. High value, high chroma. RGB=(142, 195, 16). There is a large yellow component. But it is in the Greens color family, so I suppose viewers will not think it is yellow. If I put this color on plant leaves, do you think it is convincing? When I used the high-value "Cobalt Blue + Cad Yellow" formula on some plant leaves, people said: "You should not put yellow there."

There is no pigment information on this page.

http://www.sherwin-williams.com/homeowners/color/find-and-explore-colors/paint-colors-by-family/SW6921-electric-lime/

So, now we know it is definitely possible to create non-yellow, high value, high chroma green commercial paints.

Is it possible to create similar color with art oil paints?

Mythrill
02-17-2015, 09:12 PM
I put this color on plant leaves, do you think it is convincing?


Sam, no color is convincing by itself. It's the colors around it that make sense.


So, now we know it is definitely possible to create non-yellow, high value, high chroma green commercial paints.

Is it possible to create similar color with art oil paints?

Oil paints don't suffer from being limited to 4 pigments, so you can create greens that are even higher in chroma than the one you showed. I don't see why you would want this, however. If a color is too saturated, it can steal your eyes from the whole painting.

If you want to check this for yourself, try using pure Phthalo Green Blue Shade (PG 7). This is one of the colors people hate the most when it's pure precisely because it's so saturated!

Patrick1
02-18-2015, 12:52 AM
1 or 2 years ago, Gigalot posted a wonderful forest scene he did. From what I remember, it had some very bright, high-chroma greens of sunlight filtering through foliage. It was very lifelike.

If done well, maximum-chroma greens can look great. But high-chroma middle (or especially yellowish-greens) are more common in nature than blue-greens like PG7. Hence the reason PG7 indeed looks artificial (when unmixed with other colors), while PG36 or a bright lime-green convenience color can look lifelike...if properly used.

SamL
02-18-2015, 01:27 AM
Oil paints don't suffer from being limited to 4 pigments, so you can create greens that are even higher in chroma than the one you showed.
Printer companies, such as Epson, or the printer that prints National Geographic magazine, use 4 pigments.

But Sherwin-Williams is not a printer company. It manufactures house paints for the walls. It manufactures hundreds of pigments, maybe more than Winsor & Newton.

So, art oil paints do not have an inherent advantage over a house paint manufacturer such as Sherwin-Williams. But art oil paints do have an inherent advantage over a 4 pigment print system such as Epson.

Do you know a way to use art oil paints to create greens that are even higher in chroma than the “Sherwin-Williams Electric Lime” I showed?

Patrick1
02-18-2015, 01:50 AM
Sam - how many pigments does S-W (or any house paint manufacturer for that matter) use for their house paint formulations that are mixed for you right before you buy? And how do you think the pigment load compares to artists paints?

I don't think you'll have much trouble exceeding that bright lime green with any artist oils or acrylic (unless they use a fugitive pigment - then all bets are off). If you don't already, you'll need an actual paint sample of it (not displayed on your monitor) , then try to match or exceed it using the pigments suggested earlier. I'd be interested to hear how it goes.

SamL
02-18-2015, 02:18 AM
I don't see why you would want this, however. If a color is too saturated, it can steal your eyes from the whole painting. If you want to check this for yourself, try using pure Phthalo Green Blue Shade (PG 7). This is one of the colors people hate the most when it's pure precisely because it's so saturated!
Of course, if used improperly, a saturated color can make people hate the picture.

But, if used properly, a saturated color may make people like the picture.

For example, in this picture, some leaves have RGB=(176, 253, 0). It achieved maximum, 100% saturation. But if it were a oil painting, I doubt people would hate the picture.

http://thumbs.dreamstime.com/z/green-leaves-water-14986032.jpg

So, being hated when used poorly should not be a reason to prevent people from learning the method.

I think a painter should have broad skills.

If this painter also knows what is a good picture and what is a bad picture, then an extra skill can only help, and will not hurt.

Gigalot
02-18-2015, 03:44 AM
Remove white from picture using a color, which must show the same value, bright green has. Transform picture to a CMY mode. Add more lightness to green, it will desaturate it, but psychologically it looks bright green anyway. Desaturated a bit using white, green color looks very pleasant for eyes.

Gigalot
02-18-2015, 03:50 AM
Desaturated picture must have equal value in green and in "white"

Gigalot
02-18-2015, 04:03 AM
And you can do some "flood"

Gigalot
02-18-2015, 05:27 AM
And you can do some "flood"
This picture is 100% paintable, you can copy as is and mix any color on it, using standard palette colours - PG7 mixed with PY35 Cadmium Yellow lemon or Cadmium Yellow light. However, the source picture can't be painted, it is oversaturated display color.That do not means oil paintings are always loosers.
I have a strategy, how to attack monitors crappy pictures with oil paintings. The illumination of monitors brightest places is only about 300 lumen. Into a well illuminated rooms, the monitors color looks very poor. 2x23 watt CFL bulbs, from the both sides of 50X60 centimeters painting, can give twice or even better illumination. That performs far better than monitor, and now, my oil painting beats this beast, this fake, photoshoppy color saturator. My painting glows! :D :crossfingers: Kick your LCD matrix!

Mythrill
02-18-2015, 09:33 AM
I don't think you'll have much trouble exceeding that bright lime green with any artist oils or acrylic (unless they use a fugitive pigment - then all bets are off).

Patrick, as for fugitive pigments, you can use a fluorescent green to get something really bright. But, of course, it will fade. :)

But maybe we are asking the wrong question: Sam, why do you want to particularly match that very bright green? Does it have to be 100% like that?

Gigalot
02-18-2015, 10:45 AM
Patrick, as for fugitive pigments, you can use a fluorescent green to get something really bright. But, of course, it will fade. :)

But maybe we are asking the wrong question: Sam, why do you want to particularly match that very bright green? Does it have to be 100% like that?
Do not needs fluorescent green. 4200K degree CFL lamp light will increase your visual green color, it will pop up greatly! If you need extremely bright result, just put these CFL to a light fixtures.

I am curious, can you say, guys, what you wish to get? :confused:

SamL
02-18-2015, 02:45 PM
Sam, why do you want to particularly match that very bright green?
It is because under some conditions, some plant leaves do look that very bright green, and I want to learn to method to depict it. But my first attempt failed. I tried the "Cobalt Blue + Cadmium Yellow" recipe. I started with Cadmium Yellow. I added Cobalt Blue little by little, until the value was what I wanted. But the result is pure yellow, and not green at all. RGB=(217, 217, 61). When people saw the picture, they said those areas are too yellow. I got the value and chroma that I wanted, but it seems the yellow hue became a distraction for the viewers. If I stick with the "Cobalt Blue + Cadmium Yellow" recipe, I guess I can add enough Cobalt Blue to make it true green. But it will be dark. Then I will need to add white to make it light. Then the result will be a grayish, low chroma, light green. That is not what I am trying to achieve. So I felt stuck, and I turned to the WetCanvas community for help.

Does it have to be 100% like that?
It does not have to be 100% like that photo. That photo is just an example to show that under some conditions, some plant leaves do look light, high chroma green. As long as the hue is not yellow enough to become a distraction for the viewers, it is fine.

Mythrill
02-18-2015, 03:00 PM
It is because under some conditions, some plant leaves do look light, high chroma green, and I want to learn to method to depict it. But my first attempt failed. I tried the "Cobalt Blue + Cadmium Yellow" recipe. I started with Cadmium Yellow. I added Cobalt Blue little by little, until the value was what I wanted. But the result is pure yellow, and not green at all. RGB=(217, 217, 61).


Sam, so you are saying you matched an individual color and, instead of a bright green, you got yellow, correct?

This is not a problem of oil paint at all. This is a matter of relative perception. When we isolate a single color, sometimes the color we get is very different from the color we perceive, but why?

This is due to the colors surrounding it. In the case of your leaves, there are thousands of different greens near that bright, greenish-yellow color, so it looks green to you... but it isn't. It's actually far more yellowish than you perceived, just as you mixed it.

Here is an example of this illusion:

http://www.wetcanvas.com/Community/images/18-Feb-2015/96427-tint-shade1.gif

All colors here are cool. However, because the background color and the color on the right surrounding it, you see the blue-violet on the left as a warm violet color.

Sam, I would sugest you not to apply flat, even colors. Even when colors seem flat (like in illustration), there are usually 2-3 shades of that color near it for some delicate contrast. For example: for a cartoon leaf you perceive as green, there will be at least a yellowish color around to act as the highlight, and another blueish color to act as a shadow.

Gigalot
02-18-2015, 03:52 PM
Forget about Cobalt blue color, it can't mix high chroma greens. I guess, the problem is how to reproduce exact color from picture on the display to a color on canvas.

Take PG7 and Cadmium Lemon for that purpose. Mix these paints together, until you reach proper HUE in this mixture. Illuminate the working place with the same brightness and color temperature light, your monitor has.
Now, take a picture you wished to reproduce as a painting and CALIBRATE color of this picture, displayed on screen, until the high chromatic green on the picture will reach the exact color in hue, value and saturation, that your paint pile has. After such calibration, you can paint your picture without any problems because colors on screen and colors on painting will be quite close.