They all use different coloring on specific sheets. The sheets by Divine Insect are using the "full" color format, while some, like Dr. Robotnik ripped by Dolphman are using a "raw" color format, while some, like the Sonic sheet for Sonic the Hedgehog (Genesis) use an odd variety of colors, which I fixed up. Also the K-T-E in Sonic 2 spritesheet is also using a variety of different colors, like the grabbing on to something frames, which are using a really light color.
I think they should all be in the raw color format.
I think they should all be in the raw color format.