Some fun historical context: the 74181 chip (part of the 74HC series) was one of the key technologies behind the Xerox Alto. It was the first complete ALU on a single chip using a medium-scale integration (MSI) design. This was what enabled the Alto to be much smaller than minicomputers like the PDP-8, which used small-scale integration (SSI) that spread the processor over many individual logic gate chips and circuit boards.
I wrote it a bit further down, but another solution is to use SVG's with stroke='currentColor' instead. This value uses the inherited text-color and would therefore always work.
Some fun historical context: the 74181 chip (part of the 74HC series) was one of the key technologies behind the Xerox Alto. It was the first complete ALU on a single chip using a medium-scale integration (MSI) design. This was what enabled the Alto to be much smaller than minicomputers like the PDP-8, which used small-scale integration (SSI) that spread the processor over many individual logic gate chips and circuit boards.