Just created a new folder and tried to change its color via the color wheel; but it stayed black. Found that if color is anything but #000000, it can be changed via the color wheel; but if #000000, it can only be changed by typing in a new color.
Hmmm... if I also click inside the color triangle, then the color can be changed.
I never even considered using the mousewheel here. For me, it works whether black or any other colour.
Ok, clearly I read too fast....
Saturation (S) zero always produces the same RGB color regardless the hue (H) component of the HSV model according its transformation operations¹. You can move the value (V) between 0 (black) and 100 (white) to get all grey shades in between, but hue will not affect result. ¹ http://en.wikipedia.org/wiki/HSL_and_HSV#From_HSV
OK, that make sense... I was expecting RGB (S=100,V=100) would be default mode which would allow picking any color since the expectation is to go from black to some color; not black to another shade of black. Having to adjust S & V to 100 every time seems like the least obvious default was chosen for these two values. If there was a setting, I'd choose default_H=100 & default_S=100 :) and a minor nit... :) Shouldn't Hue be restricted to 1-360 or 0-359, vs 0-360?
To clarify... no such thing as black with S=100 & V=100; but clicking on color wheel resulting in automatically moving S&V to 100 would simplify color selection IMHO.
Sure, it could be better, but unfortunately it's a standard GtkColorSelectionDialog¹ whose embedded GtkColorSelection² widget doesn't allow for such events or other customizations, AFAICS. I don't think anybody wants to rewrite the dialog from scratch, hence wontfix. ¹ https://developer.gnome.org/gtk2/stable/GtkColorSelectionDialog.html ² https://developer.gnome.org/gtk2/stable/GtkColorSelection.html