Blend (spell) and it's context.

So we all know what the blend spell does, gives an elf a +4 on stealth.
Great and all but...

"You draw upon your elven link to the wilderness to change the coloration of yourself and your equipment to match that of your surroundings."

I have a player in my group who has this on an item permanent. So he's running around in a dungeon. Thing is the spell says "WILDERNESS". He feels that the spell encompasses all the environments he is in regardless.

How should DM's interpret these spells like BLEND regarding its wording?
I mean it makes sense to say that Elves have a certain love for nature so it would only make sense that this blend spell would work in nature but in stoned worked temples, ruins, dungeons ect... I just don't see it happening.

Just wanted some opinion regarding this spell as it is pretty OP for a 1st lvl spell to be used in any environment.

Thanks.

The spell as written works anywhere. You don't have to be in a forest to use it.

Analysis: It's a first level spell that gives you +4 to a skill check and a limited Hide in Plain Sight, both of which go away if you move more than half a move action's worth during your turn, and it only works for ten minutes per level. Jump gives you +10 on a skill check, albeit for only one minute per level. Deadeye's Lore gives you a +4 bonus to Survival checks for an hour per level. All of these are first level spells. A +4 bonus to a single skill for a reasonable duration is very reasonable for a first level spell, and the hiding ability is more than made up for by the movement restriction and the fact that you have to be an elf to use it.

So, mechanically, it's just fine the way it is. Flavorwise, the wilderness fluff reinforces that an elf is a creature of the wilderness, and the spell allows him to blend into any surroundings much like a chameleon or many other animals would.

If you're the GM, though, it's your call. As a player, though, I'd feel a bit slighted if you allowed me to take this spell as written, then restricted it later for some reason.