Keyword Text Color Change

Question

I was wondering how I should go about making a TextBox, perhaps RichTextBox, to show Keywords in a seperate color. I've been able to change the text-color of ALL the words in the box...but that doesn't help, I only need certain words, chosen by me, to be colored.

I'm looking for something kind of like Visual Studio, where keywords are changed in color. Like so:

return 0;   is what we type
return 0;   is what it is changed into

If anyone could help me out, point me in the right direction, anything, it would be GREATLY appreciated!

Thank you in advance,

CSharpHurts