Ok, here's my problem: When I'm using MSPaint and creating the material image, I use the specific RGB values for cement, which is

R: 165
G: 165
B: 165

However, once I start drawing, I check the RGB values and the stupid MSPaint changes them to something that is similar to the RGB values, but different. This results in a super sensitive material that I don't want. Please help.

The .rte with the non-working materials is included below.

Try changing an existing material picture, since normal pictures and material pictures have a different palette.

Edit:
Added two files to see the difference in palette (from Photoshop).

I think paint knows about palettes, which is why my CC sprites always have the CC palette.

In other words it's getting confused about the palettes and such.