Changing color in a GIF

I need to change the color of a line drawing of a yellow to green in a GIF picture. With what program can do this?

I have spent the GIF (8 bit) with uni palette that does not include the color necessory. How to change the palette?

In PS for example, in the Image menu - Mode, which will have a color in the palette.

Sorry Gusgr8, but you require a more "refined" description.

I have a picture with a bunch of lines in one color and others in another, I want to change the green lines to yellow lines.

Thanks anyway.

As you say with PS, if an animated gif in ImageReady can do it, I think the latest version of the accompanying CS, PS8.

If that goes up the image and can be more specific, but that as soon, select the green pixels to change the green buttons in the 256 colors available. Whenever this one is green, not 2 or 3 green .. I do not know if I explained, that is, an edge smoothing over of the same color, and are not "teeth."

I got result with IrfanView.
Menu Image -> Palette (Edit Palette, Palette Improt, Export Palette).
Everything was there.

Thank you.

Glad to know that you got the solution.
And its good that you mentioned the solution here.