I think that it should be possible for the developer to choose between linear RGB and sRGB when making UI materials.
This way it would be possible for the developer to make a dynamic material where the color of the material could be changed by the player, along with other applications like having different colors for one material apply to status effects in the UI.
I did try as many ways I could find in order to fix the sRGB problem but the editor doesn’t let me do that without importing a texture.
All material processing happens in the linear color space. Gamma correction happens as a post process, so any Gamma + Linear color math you’re doing in a material would be wrong if done before the post process that takes the final linear scene color and tonemap + gamma corrects it.
There’s no reason you need to work in gamma space in the material, just let the player choose the color in gamma space, convert it to a linear color, and set that as the material parameter.
So here’s a blueprint of the material and what the material has to deal with. The fire-like symbol would have an opacity mask to have the lighter part opaque, and the darker part molded into a translucent circle behind it. The opaque color for this symbol doesn’t get corrupted while the circle thing I made (which is supposed to be the same base color as the darker part) gets a few shades lighter.
Of course character customization might not be affected, but I find the problem annoying when I’m trying to make an optimized UI because I want to use the minimum amount of images possible.