Colour Pallete

Hi
I want to make my own colour pallete (just for learning process) does any one know how I may be able to do this. I took out a VB book from my uni's library called Mastering Visual Basic and the example in that doesn't work properly. The example in that draws a grid in a picture box and tries to fill each box with a different colour it also supost to allow you to loead a custom pallet but the only result it produced is a Red gradient from black.

Can any one show me, I made a small test program which draws out a grid nicly I just need to know how I can fill it in the right 256 colour a bit like Icon editing programs.

Thanks in advance