Bring to Light lets you search out a creature, instant, or sorcery card from your deck with a converted mana cost equal to or less than the number of colors used to cast Bring to Light. This means that unless you’re running a five color deck, you’re usually only going to search out a card with a 2 or 3 CMC. You’ll always at least get a 2 CMC, since Bring to Light has two colors in its cost already. 5 mana to play a 1, 2 or 3 drop card for free certainly isn’t terrible, if a bit unexciting.
The other thing to consider with Bring to Light is that alternate casting costs don’t work - such as Awaken - and spells that would otherwise have Rebound don’t work, either, since they are already put into exile with the effect of Bring to Light and not cast from the hand. Also, for those that may want to Cascade into it in EDH with Commanders like Maelstrom Wanderer will be disappointed, since it will then only tutor up 0 CMC creatures, instants or sorceries - which exist but aren’t what you’re trying to do with a 5 mana tutor.
It’s hard to say how much Constructed play this card will get, but there are certainly three-color and five-color Commander decks that will use it. Even some Simic-colored (blue/green) Commander decks will use it to present counter-magic, since the searched card remains in exile until you choose to use it. 5-color combo decks can use it to search out combo pieces. There’s certainly some utility here, but unless some crazy 4-color combo deck pops up, it probably won’t see much Constructed play outside of perhaps Modern Scapeshift. You can also tutor up Siege Rhino in Standard by splashing Blue in Abzan.
Bring to Light should be at least a passable tutor in some Commander decks, although it doesn’t get artifacts or enchantments, which are things you’d like to tutor in that format. The power of tutors is so immense in Commander, though, that I am sure people will be jamming it into their UGx lists as soon as possible.