Color Detection using LAB Color Space

I have asked before about color detection using HSV Color Space,

Then I have been guided to used the LAB Color space as it is work for any color as Image Analyst answered me.

But my question not when I find the chroma value that is the square root of (a^2 + b^2)

after that how can I use this value ?? Like if I have the image attached where should I refer to and compare the calculated value 'Chroma Value' to a range of values to tell me that the object is red, or green

I need it to be done automatically

I have checked this demo, it helps but I didn't get where is the reference range I should use !

Color segmentation by Delta E color difference

Answer 1

[Bjorn Gustavsson]

There are a couple of submissions on the file exchange that solves this very task. Take a look at this RGB-2-color-names, or this: fuzzy-color

HTH