In (3) the symbol to be adjusted. But already in (4) it becomes clear that the text lies under the square instead of on it. Things get even worse in (5) where everything disappears under the colour.
The schematic editor currently has no concept of a z-ordering of graphical items. So your idea to draw nice colored symbols, composed of graphical items on top of each other, will not work.
Even working with the “custom background color” for a rectangle/circle doesn’t works reliable
This is a known restriction and tracked in this gitlab-issue: