Color Panel > Grey spectrum, when resizing as small as possible can cause other spectrum containers to collapse

[debraspicher]

Steps to reproduce:

1. Change spectrum/wheel type to Grey
2. Grey allows the panel to be resized very small, so resize the height as small as possible.
3. Change to another spectrum type, especially panels such as LAB, YXY, YUV, etc... it should appear but it will be occluded by the slider portion

Video: https://1drv.ms/v/s!AuWHX0h5bAoRio8-O5H8SjL2sQe11w?e=mERWyQ

[VectorStyler]

@debraspicher I added this to the backlog.