Colors window doesn't get smaller

How do I get rid of the grey space in the lower pasrt of the coplor-window (color dialogue box)
The regular way with the little arrows on the edge does’nt allow to make the grey field dissappear.
Restarted SU19, but that ![54|191x500]

doesn’t solve the problem

Does resizing work when you have the color wheel or another picker (crayon, slider) active?

Thanks Mike!,
your remark was helpfull. I discovered how to manipulate the size of the lower part bij adjusting the thin grey line between upper and lower field in the floating window.

Things are back t normal.
in Amsterdam, that is.
thanks again,