Coloured semi-transparent alpha channel TGA file

I have a dumb question ...

I know how to make a transparent alpha channel section of a TGA picture for upload into SL. It seems my brain is fried and forgot to make a coloured semi-transparent alpha channel? As in a blue glass that is semi-transparent?

Any pointers or suggestions? I am building sunglasses and could use semi transparent coloured lenses.

Any help would be highly appreciated. Sorry for the spam.

I believe if you use shades of grey instead of black and white on your alpha channel you will get semi-transparency.
-Sylvia

How would I tell a shade of grey (in Photoshop) to show as a semi-transparent shade of blue (in SL), for instance?

Thank you very much for your help.

The alpha channel only handles transparency information and doesn't handle colours.

If you want it to be blue, just make sure whatever you have in your RGB image is blue. The alpha channel will make it semi transparent.

This makes so much sense now ... thank you very much.