THIS IS NOW OBSOLETE AS IT HAS BEEN ADDED INTO 2.1.15
What it says it is. Colour changing can be enabled on an MD2 by including an extra texture titled <NAME>_blend.png. the texture should be greyscale, with lighter areas being closer to white, and darker areas being closer to black. Transparent pixels are not included in the blending, and use the original texture's colours. Included is 2 executables, one SDL and one DirectDraw, and an example MD2 and textures provided courtesy of Jeck Jims. The executables are just plain old 2.1.14 with the relevant commits cherry picked onto it.
Source code for the changes can be found at: http://git.magicalgirl.moe/Sryder/SR...2_colourchange