A slow change in colour comes to some birds during winter.
They moult in late summer and gain a new set of feathers. These feathers are often drab and plain as they are wearing their non-breeding plumage.
At the end of winter the tips of feathers wear away on some male birds and show brighter colours underneath.
For example – male chaffinches become brighter and have pink cheeks and blue heads.
This is why sometimes it is difficult to recognise birds as they ‘change colour’ at different times of the year.
Makes bird watching and feeding a bit more complicated and a bit more interesting.