What are the advantages / disadvantages of the red, green, and amber reticles? I'm trying to decide which one to get. Which is best for daylight use? I imagine they're all similar for low light use.
I can't speak for amber, but red works fine, even at night. I have a switchable red/green optic, and green leaves me with a dead-center blind spot (mild, but very noticeable) on any of 7 brightness settings, during the day. I can't imagine what it would do at night...
The above link explains (lightly) why blue is a bad choice...
Add the two up, and red is a fairly standout choice for a reticle, barring extenuating circumstances making amber a better choice. Blue and Purple would effect vision less, due to lower perceived brightness, but blue light is typically blurry(er) for most people, and purple contains blue.
