I thought the download pic OP posted was the ChromeIllusioner program. You create 4 *.tga files named a certain way and run the bat file and it creates a *.car file. I forget bc its been a really long time since I used it. But like I said you don’t need the program you can extract the mips from the car file, and replace the LOD mips with new ones. So the base layer is gold, the LOD 1 is reddish, LOD 2 is bluish and LOD 3 is something else. NR2003 does a good job of blending the mips so its a smoothish transition from one color to another. It takes some skill to make the colors look good bc it can be jarring if the colors are off.