This might be one of the most bizarre and subtle changes encountered yet, don't know what's most disturbing, Lucas changing it or me actually discovering the change. ;) I stumbled upon it by accident when matching the aspect ratio of my Technidisc LD against the 2004 transfer. Anyway, it appears that the reptilian creature seen in Mos Eisley got some color tweaks in some scenes when it was time for the 2004 transfer. Probably in an attempt of Lucas to bring some variation to their costumes, see the original green in their costumes changed to red.

Top: GOUT Bottom: 2004 DVD

Am I really correct about this being an actual deliberate change with all the color differences in the DVD and the not always accurate pallette in the GOUT? Yes, it looks like it, I've compared with all known sources and it looks like this was a deliberate change done for the 2004 DVD. Sometimes when this alien is seen in the cantina, or when Luke have just sold his speeder for example, no color tweaks were done. Not sure if there's more glimpses of them where a color tweak was done as I didn't check every Mos Eisley scene.