The part about setting up your studio at draw mix paint is very good when it comes to ideal lighting.
As for what display light to paint for - for me there is only one answer - as close to the same lighting color and intensity of the place where the art will be displayed for sale.
Since virtually all my paintings are sold in galleries that are properly lighted, I paint under light in my studio that gives the best display under those conditions. If the buyer decides to hang it in a dark hallway with no light on the painting, that is their problem (ignorance of proper art display), not mine, though it doesn't hurt to include some simple instructions about proper lighting for your work to help the clueless ones out there who might buy one of your paintings.
I would never paint something under a low lighting situation in my studio intending to make it look "right" in a poorly lit location unless this was for a commission and was known in advance and a specifically requested thing from the client.