How can I edit color table to ..

[Alx]

Hello all,

I'm not really an expert concerning graphic design.

And I would like to set the transparency color of my gif file as the first color in my color table.

I don't understand how I can do that.
I'm completely lost.

Could you please explain me how to do that ?
For information, the gif file on which I want to do that is that one: http://puzzlemaniak.com/scrollbuttons.gif

Thanks in advance for any help, it would be really appreciated.

Best regards,
Alx

 

[Gaussian]

And I would like to set the transparency color of my gif file as the first color in my color table.

Hi. Why not reading the color table backwards, because the first "color" in thas case is transparency or am I missing something Alx?