User Login block is inconsistent with the rest of the theme.

The User Login block defaults to `Dark Grey Color`. This is inconsistent with the rest of the theme (attachment 1).

It reverts to that setting on reset or `Not use this group` (attachment 2).

Setting it to another colour (e.g. White) does not affect the darker area in the centre, the textboxes nor the log in button (attachment 3). Additionally, there is a black border that does not exist around any other blocks.

Setting the block style to `Raw` uses the same colour as the background throughout the block. However, the textbox and login buttons remain darker than the rest of the theme (attachment 4).