Visuals: target <a> tags in DCR rendered pages

Highlighted by Visuals team:

"another example of something that dcr has made it seemingly impossible to do: it seems to be basically impossible now to target tags to change their colour (!important doesn't work). But we need to do that sometimes when we have different accent colours in our designs"

See thread for details: https://chat.google.com/room/AAAAVBpXHd0/3SYrTYS6l8M/3SYrTYS6l8M?cls=10