Talking about color this week. I just want to say Brown rules!
Seriously, brown is real. Brown is subtle. Brown is complex. You can have reddish browns, yellowish browns, violet browns. Changing the value as needed for composition and lighting, you can do entire paintings in brown. And yes, tan, beige, ivory, khaki, and all those light neutral colors, you can call them all brown too. Skin colors are also in that same family. You can make a brown color wheel if you wanted. I paint miniatures and brown is one of my favorite things to study. Here is a quick link to a group I did in neutral ivory and gold
(link). Here are a few more studies in brown, scattered about the townsfolk
(link).
Here is another quick experiment on color. Google "Fantasy Art" and go to Google Images. Now click on the various color filters on the left. Click on red, observe the general themes discussed in the article. I think purple is the most impressively cohesive one. It's like every purple hued image has magic (or faeries but there are a lot of faeries in any hue). Pink is what you would expect. Brown hues are easily my favorite, with Orange a close second (not too surprising, as they are closely related).
Have you noticed how magic weapons are often depicted with a blue glow? Why is that? It's because blue is one tone that brown can't have. So a blue glowing sword is always going to stand out, on any brown dominant painting. I think brown has been, and should be the dominant color of D&D. Of course red fire demons, green trolls, and house elves in purple and yellow polka dot pillow cases are always welcome, but the iconic scenery and character portraits should contain an over 50% composition of browns and tans. And it would be fitting for the D&D logo to depict this property.