This end of the year the shrubs are under pressure to make the most of the light, so I suspect, as a result, they've thrown a few green leaves. However, next year, any growth, especially new growth, which sprouts green, should be carefully cut away. Are they in a shady position? That often triggers extra green leaves as the plant tries to make up for the lack of light.

That particular Euonymus does often produce the odd green leaf or three - the thing to do with both is to check whether the plain green leaves are all clustered together on one branch, that is, the whole branch has nothing but green leaves on it. If that's the case, cut out the branch concerned, but if the leaves are mixed on the branch, between variegated and green, don't worry about it.

Thankyou for your replies. The leaves are clustered together on one branch but are not in a particularly shady position. I will remove that branch as advised and shall check again next year