TSVB color picker does not fully open

[dschneiter]

Kibana version: 7.6.0

Elasticsearch version: 7.6.0

Server OS version: Linux

Browser version: Chrome

Browser OS version: macOS Catalina

Original install method (e.g. download page, yum, from source, etc.): tarball

Describe the bug:

When trying to pick a color from the palette to color the bars in a TSVB Top N Visualization, the color palette doesn't render in full. It get's cut off at the bottom of the browser window and no scroll bar is selected. Could it be related to #52084 ? I don't see any scroll bars at all...

Steps to reproduce:

1. Fresh install
2. index some time series data & define the index pattern
3. In TSVB Top N Panel Options try to set the bar color to any color

Expected behavior:

Screenshots (if relevant):

Errors in browser console (if relevant):

Provide logs and/or server output (if relevant):

Any additional context:

[timroes]

Duplicate of #52084