@ADivineCanine! I know your post is a few months old, but I'm new to the community and just thought I'd suggest something else as well.
Before I got into yoga, it used to bother me so much that the majority of women's tights that we sold were black. Then I went to my first hot yoga class, had your same issue, and immediately understood. 😂
How has your summer been? Have you tried any of the suggestions so far?
The one thing I wanted to add was that I now hike in a skirt and it has been activity-changing! I do not hike in "skorts"... the liner defeats the purpose, IMO... if I wanted to hike in shorts, I'd be hiking in shorts. I found this amazing skirt from Mountain Hardwear... it's light, breathable, AND HAS POCKETS. I find that the increased airflow of a skirt, and not having a bunch of fabric between my thighs, makes my outdoor activities much more bearable. I don't even really chafe when I wear it because it keeps everything dry, even though I chafe in shorts when I run. If you try out a skirt, maybe take a thing of Body Glide with you the first time or two to see if chafing will be an issue for you.
I hope you've had a good summer thus far with lots of safe outdoor adventures!