Color-picker dialog is different, depending on from where it's called. Better to make it same?

[Stub]

Hi,

>From several parts within kdenlive I can or have to choose a color
with a 'color-picker' dialog.
The color-picker dialog looks and behaves very differently, depending
on from which gadget it's called.

I suggest, if possible, to unify this behaviour, so that the same
color-picker dialog is used for all color related gadgets.

Regards,
-S.