Select cells and then run a macro to lighten/darken the interior colour of all cells

[Richynero]

I have a table of data which has quite afew columns. I find it easier to read the columns if each row is a slightly different colour, (white and a very light grey is my normal preference).

Now, the table I have at present is one I have inherited. Some of the columns are coloured light yellow and a few more light green, while the majority are white.

I want to be able to highlight a single row and then run a macro which makes the the interior color of each cell either a tad darker or a tad darker.

I have been playing around with interior.color and interior.colorindex and cant work out how to do this. I wanted to convert the color into an RGB so I can work on it but dont know how to do that either.

I found this http://www.cpearson.com/excel/colors.aspx but cant seem to get any use out of it. Final question, what is RGB long as refered to in this link?

Thanks one and all...

Richard

PS: I dont want to just have all the cells go the same color, I know how to run a little mod 2 in conditional formatting but I want to keep the existing colours just tinge them a little.