Problem

rcParams["axes.titlecolor"] defaults to "auto", i.e. use text.color. On the other hand rcParams["axes.labelcolor"] (the color of the x/ylabels) defaults to "black", i.e. changing rcParams["text.color"] doesn't affect these labels).

Proposed solution

Add support for rcParams["axes.labelcolor"] = "auto", meaning to use the default text color, and make that the default rc value.

For bonus points: rcParams["x/ytick.labelcolor"] currently defaults to "inherit", which means to use the tick color. If we change here the spelling of "use the fallback" to "auto" (#28154), we could use that to also make "auto" mean "use rcParams["text.default"]" instead of rcParams["xtick.color"], which seems actually more consistent, especially if we also switch the rcParams["x/ytick.color"] to defaulting to the defaulf spines color (rcParams["axes.edgecolor"]) -- again, making the tick colors match the spine colors seems more important, to me, than making the tick colors and the ticklabel colors match by default, but ymmv.