Digital, lighter and slower than you may think with well lubricated finger in a well lit room with my genitals in plain view and hood pulled back for direct clitoral stimulation. Tell me what you noice visually and physically with out expectation of anything being done in "exchange." Thank you for asking!
Usually more about the changes they see visually at first, and later on the sensations. One guy made a list of every color shade of white, pink, red and purple he could find and started using them to describe what he saw. It's a big turn on for women to have their pussys described that way, but 999 out of 1000 would never ask for it.
Only one gal asked me if I would like to use a magnifying glass to take a closer look - I said no thank you at the time because I was just to Shy LoL
You are correct about the range of colors that take place - Labia expands and the Clit may pop out of the hood, or is some cases is always out. As everything gets wetter the colors become more vibrant.
Reminds me of the time I was in an RV on a ski club trip - Wine country club event and we had been watching porn flicks until bored with them. One evening a bunch of friends, mostly women came in to join us and they were watching a video we had already viewed too many times
I will never forget the gal who saw a close up of a Vagina and said " So that is what it looks like" Considering she was at least 30 years old and clearly had never used a mirror on herself -
Then again the one she was looking at may have been very different then hers - I should have told her they do vary LoL
This reminds me of one of my latest encounters with my ex. I had just come out of the shower when he said he wanted to inspect my pussy. So he had me on the bed and proceeded to do his inspection by spreading my legs apart and kneeling between my legs. Just when I asked him to tell me what he saw as I felt his fingers spreading open my lips, I felt his tongue up and down my slit, flickering on my clit as he had pushed back the hood during his inspection. Of course, I don't think he ever heard me except for my groans when he gently sucked on my clit.