\"green\" vegetables & \"red\" tea

So I understand it sounds naive to use the word \"绿\" when describing vegetables, i.e. \"青菜\", but what if you truly wish to communicate that a certain vegetable looks very green, perhaps a deeper green than another vegetable. How would you say \"spinach is a deeper green than celery\". I assume you would not say \"菠菜比芹菜更青\"? If you were a painter, what color would you use to paint spinach? Presumably not 青色 paint, but 绿色. At least, it wouldn't sound awkward to say 绿色 would it, in that case? Now, how about tea? I know \"红茶\" is our \"black tea\", so what about red tea? Thank you!!