Everything's Gone Green.

Eurasian (Common) Green-winged Teal, originally uploaded by Len Blumin.

Well, it may as well have done for all the use these ruddy colour-blind eyes of mine are for identifying birds. Take the Teal, for example, still hanging around on the Irwell near Peel Park in Salford. My identification notes for him said "Dark head, side-stripe, diff col. tail"; I then had to take that pattern and apply it to various duck-shaped possibilities. In the end, after discarding a small number of possible rarities, for various reasons, I alighted on Mr. Teal. Identification had been made easier because he had The Mrs. with him, and the pair taken together are fairly distinctive.
I've had to learn to use patterns in identification to such a degree that unless the colour on a bird is blatantly one of those I can confidently identify (such as the vivid blue found on the back of a Kingfisher) I don't use it. Identifying a solo redwing, particularly when framed against the bright low sunshine we are currently enjoying, is a right pain in the arse, but my job is made easier if I see 80-100 'redwings' flitting from tree to tree. I don't need to see the red stripe then as I'm very unlikely to see a large flock of thrushes. Am I?
A further wrinkle is the change made in some birds between their Winter and Summer plumage. The Little Grebes on the Irwell also caused me some confusion as they're currently 'between coats'; the darker winter colours are being replaced by the more varied, and lighter shade of their summer outfits.

Thanks to Len Blumin off of flickr for the use of his picture of a Eurasian (Common) Green-winged Teal.