'green cover' is correct and usable in written English.
You could use it in a variety of contexts, for example, "The book had a green cover with gold lettering".
By C. W. Shepherd, M.A., F.Z.S., published in London 1867 by Longmans, Green, and Co.; has a green cover.
And, with the familiar green cover.
This technique presents intra-city green cover pattern analysis.
This study focused on green cover in an urban area.
Green cover in early spring ranged from 0 to 60% amongst the three crops, with camelina providing >25% green cover across all four site-years.
Seventeen spots across the city have been chosen as sites for green cover.
When green cover is damaged, it leads to greater proneness to floods.
But many environmentalists say the panel merely provides green cover to industry.
In these cases, slugs miss the newly emerging plants and feed on the green cover crop.
Monsarrat and Mulrooney, wrapped in their green cover, now sit beside Sherlock on my shelf.
So their white toilet with a fuzzy green cover was a marker of progress.
