All of the most powerful texturing applications require a color ID map (Substance Designer, Substance Painter, Quixel DDO). I've been using a Maya plugin called Nightshade Blockout to export color maps for use in these programs. Nightshade may be one of the most-used plugins for texture artists abroad, simply because it's referred and linked by those giants.
I would hope it's as simple as assigning a material color and baking the texture, but it's safe to assume such a map wouldn't come with edge padding (extending the boundaries of each color island by a certain number of pixels, to hide seams during the texturing process).
If there is a Blender workflow/plugin for this, I would love to know about it!
Thanks for reading,