Hi drdavidhartman
welcome to the Apple (user-to-user) Community.
Re: Is there a visual bias adjustment on iPad?
Am no expert in this area, and do not know. If you do not receive a satisfactory reply to your post to the community here, seems you may want to contact the experts at Apple for their advice, or to make a "feature-request".
You can see: How to contact Apple for accessibility support - Apple Support
or
You may want to visit Apple's Accessibility Support Website:
(NB: You can "Get Support" (online chat / phone/ email etc.) from the link at the bottom of their website:)
Accessibility Support - Official Apple Support
or
To provide feedback about an accessibility feature on an Apple product, email the Accessibility team: accessibility@apple.com.
All the best :-)