http://i422.photobucket.com/albums/pp309/Kohaku9595/COLORTOOK.png< br /> 1. Color picker
2. Pick color
3. Click on the box I circled
4. Up is lighter, down is darker

This is the same for : MS paint, GIMP, and SAI.

Imagine-- Could you make like an image tutorial? Its ok if your busy but thanks for answering anyway :D here lemme show you the example on what I mean http://www.animationsource.org/balto/en/chars/Mckenzie_LF/37774.html =3

I render through photoshop which allows me to make layers for my drawings.

1. Layer: Lineart
2. Layer: Color
3. Layer: Balto Screenshot background.

I am able to 'lock' my Lineart layer so I can ONLY color on the lineart. Gimp may have this ability too. Next I use the eyedropper tool to select the fur color and find a color remotely darker to it in my color pallet. After I have my color I just draw on the lineart. This is how I go from Black lines to colored lines that are the same as the fur.

For MS Paint there use to be ways where you could color over only 1 color (Make your lineart black to do this) but I'm not sure if it's possible for the new MS Paint. Again, just use the eye dropper tool and color pallet to find a darker shade of the fur and color over the black lineart.

If your asking how to trace the outside lines on the character you're rendering...

It should be easy. I just trace everything in the darker shades. GIMP should definitely work for that, since MS paint doesn't let you trace when you want to fill stuff in.

So...use GIMP 2 then. Just trace in the darker shade on the edges. If you need more help, I can give you more guidance