Q: Early 2015 rMBP 13" white spots on the screen visible only on dark backgrounds. (they are not the same kind of white spots people experience on white backgrounds, I think. ) . What are my options?

Hello there, VladishMacbook.

It seems you are seeing display issues on your MacBook Pro. The following Knowledge Base articles offers up great, in-depth steps for troubleshooting issues with your built-in display:

Apple computers: Troubleshooting issues with video on internal or external displays - Apple Support

If after reviewing the applicable recommendations for built-in display, you may want to review the information mentioned at the end of the article:

For assistance with Retina displays, please see Frequently asked questions about using a Retina display.

If you tried all of these steps for your display and the video issues persist, contact Apple technical support or take your Apple computer to the nearest Apple Store or Apple Authorized Service Provider (AASP) for diagnosis. If you plan to visit an Apple Retail Store, make a reservation at the Genius Bar using http://www.apple.com/retail/geniusbar/ (available in some countries only).

Note: Diagnostic fees may apply for issues not covered under warranty or the AppleCare Protection Plan (APP).

Thanks for reaching out to Apple Support Communities.

Cheers.