Note: You will need to right click in this so if your mouse has only 1 urr... clicky thing then this is not for you.

First Get a sprite sheet(or anything that uses a certain amount of coors multiple times).

Here we will give tails grey fur:

As you can see I already got the colors I want.
Now use the Eye dropper tool

Left click one of tails' colors.
Then right click the color you want to use to replace the color you left clicked.

Now switch to the eraser.Set it to a big eraser(If you want it done fast)Then right click through the whole sheet.

Wow! its just lke magic!
No more paint bucketing through the whole sheet.
Rinse and repeat to finish the whole sheet.
All in 5 minutes.

You are allowed to use this tutorial anywhere. But I want credit.
Please.