Is there a way to find a lighter and darker shade of a RGB color programmatically?

[Ken Corey]

On 15/02/2012 11:15, Keith (Gulf Breeze Ortho Lab) wrote:
> I have a problem... If a user selects a color and I put it into a variable (as RGB), how can I find a shade that is several shades lighter, and a shade that is several shades darker, also in RGB format?

Here are a few approaches:
http://goo.gl/RrzKD

-Ken