The Coal Tit is a small tit, in fact the smallest European tit, and could be confused with the almost indistinguishable Marsh Tit and Willow Tit if it was not for the white patch on the nape. While it behaves like a Blue Tit, there is no blue in its plumage.
The upperparts are a olive-grey, the underparts buff coloured. The crown and large bib are black, while the cheeks and nape are white. There are also two white wing bars on each wing - this feature separates it from the Marsh and Willow Tits if the nape is not visible. The legs are blue-grey.
Juveniles are browner above, and the underparts, cheeks, nape and wing bars are more yellow.(LINK)