color index for red

Hi i have a 2828 lcd and i am trying to find the color index for red no matter how much searching i cannot find it and to manually test every color index from 0 to 255 is not viable
it should be a very easy find but seems not i have spent 2 hrs ytrying to get red to display just cannot find the correct colorindex value
it should be a very easy find but seems not i have spent 2 hrs ytrying to get red to display just cannot find the correct colorindex value