[gPalette] Incorrect value for "transparent" used in findColor()

[prl]

In gPalette::findColor():

    if (rgb.a == 255) /* Fully transparent, then RGB does not matter */

255 (0xFF) is not the Alpha plane value for "fully transparent", it's the value for "fully opaque).

Should be 0.

[prl]

Just wrong. 255/0xFF is in fact transparent. The code is correct.