I don't like the suggestion and assumption that because I utilize the CR system I am devoid of any sort of higher judgement. I understand that there are low lvl cr's that don't work and high lvl cr's that don't work and cr's that seem perfect but just wind up doing nothing to the party, and cr's that seem perfect but can wipe out the party if poorly handled. I always cross check my parties abilites to the encounters I throw them against. With a party of six, and the nature of the encounter, the color spray would have hit, at most, two players. These players would have taken a good deal of damage if they were knocked out, but the other 4 players would have easily been able to come to their aid well before they died, so your "save or die" theory is out. If they didn't get knocked out by the first one, there were other spells and tricks available. Also, just because of good forture or educated play makes an encounter easier than intended doesn't mean I should fork over less XP. Yes, if I send a band of undead against a party of 3 clerics, then I would give less points, but assuming the party was just lucky or handled a situation better than expected does not mean that you shouldn't reward them. It is played with dice instead of full DM arbitration for a reason. You're playing the odds as well as the tactics of every fight, and if you get a little lucky, then you got lucky. It could have just as easily turned around and caused more damage than intended, but unless it was because I overcalculated the parties abilities, I shouldn't reward more. The dice land as they do. You should not withold a reward that could have been earned just because the enemy performed poorly.
It was not circumstance or "wonkyness" that affected the encounter. It was luck of the dice. Had the color spray caught, it would have dealt a lot more damage to the group, and been an ideal at level encounter.