What is ostinol colored reaction

Ostinol is a natural coumarin derivative, a type of organic compound found in various plants. While coumarins can exhibit fluorescence or color changes under specific conditions (e.g., in the presence of strong acids or bases, or under UV light), there isn't a single, named "ostinol colored reaction" that is universally taught or referenced as a specific diagnostic test.

It's possible this term refers to a very specific experimental procedure, a particular analytical method, or perhaps there might be a slight misunderstanding of the term.