color detection

Question

hi

i wanna to filter every color in a picture except light orange til dark orange

i wanna to remove the other color ranges

also about yellow and green

i have the code to threshold but i don't know what ranges should i use 

// threshold values for each channel

 var thresholds = new[] { new TRange<int>(70, 230), new TRange<int>(100, 255), new TRange<int>(140, 210) };

what numbers should i use in Tranges for each above colors ?

thanks in advance