I was originally going to post the above photo, as is, by itself, but I kept looking at it and not liking it. It made me twitch a bit. The reason being: this was a perfectly two-toned beetle, a red and black tab of dimples in real life, but slicked over with a greenish, tealish sheen in my photo. So after letting it sit in the “on deck” folder for a while, trying to forget it, I pulled the image back up in GIMP and in about 5 minutes (if that) removed the offending color cast. How did I do it? In a few easy steps: 1) Duplicate the base layer; 2) create a fully transparent layer mask (black); 3) select the dorsal area using the Scissors selection tool; 4) Bucket fill the selection white (so future changes to that area would show); and 5) open the Hue-Saturation dialog and set the Saturation slider to “0” for the green and cyan colors individually (I also set the Overlap slider to “50”). And presto:
I might have used the heal tool on the mask to blend out the edges although it wasn’t much touching up if I did. So a little more than a few, I guess, but still straightforward enough. Helpful in this case, is that the result I wanted was black, so I didn’t have to futz around; desaturating all the way got the job done. In truth, I could have done a bit more color correction, as the red stripes show a yellow-orangish cast when it was a solid red (which let’s face it, would just look better). I’m kind of feeling bad about it (lazy me!) as I write this up, so I better just post this and save that correction for a future post or I won’t get anything out today!
EDIT: Ok, did a real quick and dirty fix of the red stripes!