filtering specific colors

How do you make a specific hex color in an image become transparent. such as the blue (0000ff) in an image being removed and made transparent

i don't think this can be done unless mabey java can do it, javascript can't. or mabey css with a filter, i don't know.

you have to do it in the graphics program that creates the .gif

You have a choice of different types of transparency, e.g. index, alpha.

You can set the current bg color of the image to be transparent, or specify your own etc.

All graphics programs can do this (well all decent ones lol)

Merry Christmas Everyone!

::] krycek [::

oh... I did not know that gif can have alpha transparencies!!
thanks!!! I had some animated gifs, and wanted to have parts be transparent. will the png for IE transparency trick work with gifs?? or is it different?

I don't know the details of how to do it, but you can create PNG images with transparency using the GD Library in php.