EU citizens (some of whom could be non-white of course) would be included under "sec pupils whose first language is other than English", together with other nationalities (coloured and otherwise) whose first language was other than English, e.g. Russians.
Under the heading "sec pupils non-white British" would be included pupils who were descendants of, for example, West Indians who moved to the UK in the 1950s or earlier who would have English as their first language.
The figures need very careful interpretation, particularly the last two columns and especially if you are trying to relate the two of them to draw some sort of conclusion.
My wife, as a white foreign national with English as her first language doesn't get a look in, although she says that the difference between San Franciscan accented American English and West Riding of Yorkshire English in effect meant that she was speaking a foreign language so far as her classmates were concerned and vice versa when she moved to the UK.