@tsarstepan,
The term for it is "daymark" = the daytime identifier of an aid to navigation.
(In the dark, on the other hand, each lighthouse has its own light identification with different colours (red, green and white or yellow) as well as different light duration and light frequency.)
It does not necessarily have to be red and white, although this is the most common colour.
Green and white is also more common, and sometimes the colour of the daymark is changed. (The Schleimünde lighthouse holds a special record from 1890 to the present day: no other lighthouse has changed its daymark colour as often as it has. First yellow, then dark grey, then yellow again, then light grey and then diced red/white like a chessboard, then diced black/white, it now bears the daymark white with a green band after white with a black band.)
