Breaking: #62039 - Removed TBE_STYLES[mainColors]

See forge#62039

Description

The values within $TBE_STYLES[mainColors] are redundant and can be completely defined via CSS nowadays. The corresponding PHP leftovers are removed from the core and have no effect anymore.

Impact

Setting the variables within $TBE_STYLES[mainColors] and using the $doc->bgColor* and $doc->hoverColor properties of DocumentTemplate have no effect anymore.

Affected installations

Any installation using an extension that is overriding skin info via $TBE_STYLES[mainColors].

Migration

Use CSS directly to modify the appearance of the Backend.