Help.

Ok i'm adding some monsters i got from a site and when i try i get a "Invaild Color Depth." What do i do? (I'm using RPG Maker 2K3.)

It's probably just in an unreadable color format, if you have Adobe Photoshop simply change it to RGB coloring, save it, and try again. Either that or it's a corrupted file.

Usually I get that error when I try to add a 16million color image file by accident.  Use an image editor to reduce it to 256 colors and it should be fine.

I would suggest not to use MSPaint though, as it distorts the colours a bit too much.

Are there any programs that will reduce the bit depth to 8-bit, that are free?

I think GIMP have that function. I don't know, but you could try it: http://www.gimp.org/