I searched, but i didn't found what i need. So i wrote it by myself.
A simple color picker. Retrieves the color under your mouse pointer and shows it in AutoIt-friendly hex format.
Press the button, to copy the "0x......"-value into clipboard.
Hit the [Ctrl]-Key on your keyboard once, to lock/unlock the GUI.
That's all. Happy programming.
#include <GuiConstants.au3>
#include <Misc.au3>
GuiCreate("ColorPicker", 170, 80, -1, -1, -1, $ws_ex_topmost + $ws_ex_toolwindow)
GUIS