[txhurl]

Think so? Like at night?

I can see 2500 shades of blue in the daylight.

[muawiyah]

There are any number of ways your blue receptors can be disrupted ~ one is to use Viagra.

Old age can slow them down as well.

A test ~ mark a white sheet of paper with a yellow pen. Turn out the lights. Turn on a bulb that emits only blue light.

See the yellow markings? If not you may be blue blind.

[Tolerance Sucks Rocks]

I can see 2500 shades of blue in the daylight.

As an aside, are you a man or a woman. I hear women can distinguish slight differences in color better than men can.