I have heard someone requiring HSY' color picker, I don't know HSY', but it seems wrong at some color region at my first glance. to my knowledge, I know HCL is the best. it has appeared on gimp a past year. but it is derived from CIE full gamut, so I don't how they translate to fit sRGB color space ...

switch back to the previous tool after keep pressing hotkey of another tool for a particular time (2-3s)