I've made sprite sheets many times before, but now gimp is messing up. Bucket fill, colours a space gray rather than teal. I cant figure out how to fix it, (I havent tried purging gimp yet). I made a video of the problem, but It would appear I cant provide that directly. Here is a link to the video of the problem:
SnapOverflow
Indexed mode
The Indexed command converts your image to indexed mode. See indexed colors in the Glossary for more information about Indexed Color Mode.
You can access this command from the image menubar through Image → Mode → Indexed, and in my case, set it to RGB.