I got the idea from Paragon_Ninja29's InvertCraft and Andy1400's InvertCraft.Paragon said he used the Invert Colors tool on Paint.net, and I had to see what other tools there were.

Additional Notes

You need the HD texture pack fix to use this. This pack is not HD, but if you don't use the fix, the water, lava, grass and possibly leaves will still be colorful.

Note: If you're going insane from the lack of color, dye some sheep. Their fur can be colored, but don't take off the wool, it turns sepia.....ish. Redstone is also red.