How to segment images based on colour?

I have a RGB image of with n seperate colours seperated together to form a coloured pallete. I need to segment this image into n parts based on their colours and find the average of the Y values of these n segments. How should I proceed?

[Adam Danz]

This similar question contains 2 answers, either of which will get you started.

https://www.mathworks.com/matlabcentral/answers/592402-how-many-colors-with-their-name-present-in-the-image#answer_493348

[Subhransu Sekhar Bhattacharjee]

@Adam Danz Can't thank you enough for this.

Answer 1

[Subhransu Sekhar Bhattacharjee]

https://www.mathworks.com/matlabcentral/answers/592402-how-many-colors-with-their-name-present-in-the-image#answer_493348

[Subhransu Sekhar Bhattacharjee]

Credits: @Adam Danz