make nomenclature of "palette" or "hexplt" consistent

[earthbound19]

Make nomenclature of "palette" or "hexplt" consistent in all code, comments, and script names.

That will mean updating inter-script calls on updated names.

It's different and inconsistent depending on whether my neurons fired strange or down at the time I made scripts.

It's actually a usability problem. I just spent too long finding a script because I was searching for "palette," not "hexplt."

"Palette" is more immediately understandable.

And technically it should probably be the more lengthy "sRGBpalette," to admit the possibility of a variety of future palette types. And for more technical detail/accuracy.

Maybe even "sRGBhexPalette," because it's only a convention of mine that I store sRGB color codes only as hex color codes (0-9a-f). But triplets of numbers from 0 to 255 is another common convention (which I don't use).