Have you tried the Phthalos?

If you want to tone them down, burnt sienna can help.

Personally, I am drawn to the Phthalo colors. Aqua has been a favorite.

They are unusually strong, though. A little goes a long way.

You might try mixing them with plenty of medium, or medium plus water. You could also try water-diluted watercolor-like washes.

You can go back over a wash with subtle glazes to warm the horizon or deepen the upper sky.

…What am I missing ?

Another thing you might want to explore is how to do a graded wash.

This is something that is more often taught in watercolor. There are probably some threads there, in the watercolor forums; and there is certainly much information available in books that cover techniques in watercolor.

Acrylics can be used in the same way, diluted with water.

I think you would be happier with your results after learning how to do this.

It probably works best on watercolor papers, but canvas and other surfaces can be used in a similar way.

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If you have access to Barclay Sheaks’ book on acrylic techniques, he covers something similar (a variation on the usual graded wash techniques), but with acrylics. He calls it the diluted-edge technique. It’s in his section on soft edges, on pages 48-49. Basically, as you work your way down from top to bottom, you add a bit of water at each step downward, pulling the paint down into the water. Each step down means more water and less paint or pigment, so the color gets gradually lighter with each step. You just keep ‘diluting the edge’ as you work down.

The surface is not pre-wetted. The small additions of water are made with the brush, at each step downward as you work your way down.

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There are additional techniques as well, for achieving these sorts of gradations. One of them: You can put down an underlayer of white acrylic gesso, and then begin at the top with the blue color(s), going all the way across in a band of blue, and then working your way down with small figure-eight strokes (or X’s), blending the blue into the gesso as you go.

As you work your way down, if the gesso remains wet or damp and blendable, the blues will get lighter and lighter automatically as they are diluted and mixed with the gesso.

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The watercolor wet-on-wet techniques are nice to know how to do. They aren’t that difficult, if you can find some good instructions. You could give them a try. Keeping the surface wet or moist (but not too wet) is important. You get a feel for what is the right degree of wetness — not too much, not too little. It takes a bit of experimenting, and then it will fall into place.

I use different mixtures depending on the look of sky I want. But my favorite for sky does involve Pthalo blue, with a tiny touch of yellow added, and then blended with gel medium (not water!!!) to get the shade I want. I usually use gradations of that shade, as skies do vary even within the same scene, depending on where the sun is in relation to the scene, time of day, how much cloud cover there is, etc. Here in the east, I’ll add more white than out west, because the air is generally more humid here, scattering the blue more.

Dayle Ann

The best way to make the sky look really bright blue is to slightly tone down the other colors in the painting. Its not really how bright of a paint you can get, but how the paint relates to the colors around it. Everything thing in a painting is relative. Here is a little chart I did to kind of show you what I mean. The bottom big blue dot is the one the the middle and on the sides of the colors. Then I put a light blue dot inside it to judge the light colors better. Notice how the blue looks different with different colors.

Christmas Morning – after Maxfield Parrish

Kathrin – don’t know if this will help, but painted back in 2005 – I did the sky with graded washes and would only have used Liquitex Brilliant Blue (similar to W&N Cerulean) and Liqu Ultramarine – cos they’d be the only blues I had then! (Plus tit. White)
I’d also have used water only – didn’t use mediums.

Kathrin I have to agree with Kim, to be brighter it’s what’s around it not the paint itself. The paint you have will work, the less white or mixing white you use the less ashen your blue will be so you can liven it up with a touch of crimson but very very little if you want, it won’t look purple just this side of bright but pale periwinkle actually but you don’t need to do that.

Straight out of the tube watered down, Cyan Blue or they call it Primary can do it as well, you can start light and deepen as you rise, using only water and not loose the depth of color either, if you’re gonna put in some clouds
that blue will make them stand away if you haze out the edges and shadow underbelly very little with a good Payne’s grey, the one that is more blue then gray..Old Holland makes a fabulous Payne’s gray.

You’ll do fine sweetie, you have lots of suggestions here and as it is I think it’s looking good, be nice to yourself stop agonizing…haha

Hugs,
Elaine