Shame! Moral of the story; next time your better half sees an unusual bird get even a crappy piccy on the mobile
Its very hard to convey birds seen and not identified, even for birders often. A recurring example are "yellow" Corn Buntings loads of them Of course they are in fact bright buff - in sunshine/bright light. Certainly throws ideas for folk trying to work it out. If it was actually yellow below, like a banana, then you could maybe look at american warblers, or tanagers, but it would be more likely to be an escaped captive bird than that by far (or Siberian Blue Robin).
Mind you, its that time of year....
edit:..and Steve's suggestion is a good one too?
Corn Buntings. loads of them! I wish there was here Simon your lucky to see or hear a single bird here in derbyshire now at any time I can remember flocks of between 50 and 100 birds on occasions in the winter months in the late1980s and into the 1990,s in south east derbyshire I wonder if or when they,ll start comeing back here.