https://github.com/flutter/engine/pull/39932/files (issue #121563) added sRGB access for the pixel data of wide gamut ui.Images. There should be a way for users to query the wide gamut data though.

Design doc:
https://docs.google.com/document/d/1JUvx3N21Dq-GmzveNOUDixVL0hUKyrkDL5WCuPUPudQ/edit#