07-23-2020, 03:11 AM
(This post was last modified: 07-23-2020, 04:19 AM by neurolurker.)
For a start you might try Colors: Desaturate. And then select Desaturate from the flyout list. This gives you five modes of grayscale and about 20 ways to blend the grayscale and color image. The differences between some of the modes may appear subtle but may become more important as you work with other GIMP features.