It comes across as being about skin color because the GOP believes they correlate has a well-known history and continuing strategy of racism against blacks.

The whole thing could be fixed by designing an inherently fair algorithm to automate the districting process

Here’s a fabulous nonpolitical video for you. TL;DR: you can make algorithms that are SO MUCH BETTER at gerrymandering than the current political process and even produce districts that appear to not be gerrymandered, but which profoundly decide elections.

An algorithmic approach is honestly the worst possible response to this. Districting is inherently political and so the process behind it must be political. In the two-party political system of the US, that means a bipartisan commission to handle districting. Several states have implemented such a system and they do not get in the news for gerrymandering.