I'd be interested to know what kind of a tree you bought. It it for bonsai? It is already trained? A picture is worth a thousand words since too many trees have light green leaves. I have a few varieties of ficus but I wouldn't say their leaves are light green.
By the way if you pinch a new growth tip or tare off a leaf you should get white sap, that's usually good indication it a ficus or something similar. . . hope it helps. Also lots ficus have white dots on their trunks and branches such as in ficus tiger bark/retusa . . .
ficus, maple, elm, juniper, pine