Finally, if your terminal’s ANSI yellow isn’t readable, maybe see https://www.mavit.org.uk/termcolours/ or https://www.mavit.org.uk/tango-putty/
Another alternative would be to set a background colour for coloured text, but some people would consider that ugly. I don’t think there’s solution that makes everyone happy.
The question remains, is it a good idea to have an “unbreak this broken behaviour” setting? One alternative would be to make SYSTEMD_COLORS=auto-16 the default, but that fails for people who don’t have the ANSI colours in their terminal configured for good contrast (some well-known terminals, such as PuTTY and XTerm, still have poor defaults for this use-case, for one colour or another).