i remember looking around for this a while ago and found nothing. with 4k+ displays these days finding the cursor is sometimes frustrating.
and the cursor radar thing is annoying to use
As an aside, the Accessibility settings in both macOS and iOS are generally worth looking through, whether or not you consider yourself disabled. There's a lot of general quality-of-life settings and some neat features hidden there!
I think cursor customizations died with memory safety.
Windows (as of 11) still has the same custom cursor capabilities it's had since Windows 95, plus some bits (it can generate cursors with custom colors on the fly now). Applying custom cursors is pretty easy, and the 95-era properties sheet is still readily accessible (besides cursor schemes, there are other options there that haven't migrated to the modern Settings app).
There are options for pointer size, outline colour and fill colour. Go nuts.
Infamously changing the pointer colour caused a huge memory leak when it was first implemented a few versions ago, hopefully that's fixed now.