While everyone leaps aboard the outrage bus, it is important to step back slightly and actually UNDERSTAND why what he said is so upsetting to many.
I accept is is extremely difficult to find a single word that describes those footballers (and any one for that matter) of other than "caucasian" heritage that does not offend someone .. but the use of the word "coloured" is certainly offensive to a great number ... why you might ask ??
It simply harks back to the days of legal segregation, mainly in the USA, but also in places like South Africa, where the whole basis of segregation was not based on "white/non white" - which would have been bad enough - but on "white/coloured" - where "coloured" = "non white" - and that is how things like buses, drinking fountains, shop queues, entrances to hotels, and a thousand other places/things were labelled ....
"Whites" were free to enter at will, "Coloured" were pointed away/banned/refused ... so the term "Coloured" came to mean "2nd class citizen" or worse, as it implied that "whites" were somehow "superior" beings... it is that element that makes the word so upsetting.
You may not like it, and may argue it is just a word to describe a "non-white", however the phrase "white" in itself is inaccurate .. we all have some sort of skin colour/tone so are all "coloured" to some extent, but we were never oppressed to the same degree, simply based on our skin tone.
Greg Clarke should simply have known better, and has rightly gone, it now matters that his replacement actually thinks before speaking.