The different colors of the Incredible Hulk symbolize different things, and it's important to keep them straight. After all, you might want to give a Hulk comic or toy to your sweetie for Valentine's Day — but which Hulk symbolizes romance? The red Hulk or the green one? Don't risk picking the wrong Hulk and smashing your relationship. Consult our handy Hulk color-matching guide.

Pasty gray. Originally, Stan Lee and Jack Kirby intended the Hulk to be gray. But the printing press kept having trouble with the Hulk's color and he kept coming out green. So he only spent the first few issues of his comic being gray. The original, gray Hulk is sort of surly and crafty, and is very much a riff on Mr. Hyde.

Bright green. For most of his first twenty years or so, the Hulk was green and very stupid. He settled into being a volatile child, alternating between curiosity, petulance and rage. Some writers, especially Len Wein, would give the Hulk incredibly long speeches in baby talk. Here's a free verse poem the Hulk recites when some trees and rocks come to life and attack him, from an issue of Wein's Defenders:

Even here — even in peaceful forest — they will not leave Hulk alone!
Wherever Hulk goes, enemies follow him — try to hurt him!
Why? Hulk does not know! All Hulk does know is —
When enemies attack, Hulk fights back — and smashes — HUH?
Is not enemy — is tree! Hulk is attacked by — tree??
Wha —? Now other trees attack Hulk — and rocks — flying rocks!
Hulk is confused — doesn't understand!
Hulk LIKED trees. Hulk LIKED rocks.
Hulk thought they were his friends — Hulk's ONLY friends —
But if peaceful forest attacks Hulk, too — then Hulk has no friends —
and Hulk will crush anything that gets in Hulk's way!
Do you hear Hulk, rocks?
Do you hear Hulk, trees?
Leave Hulk ALONE — or Hulk will make you REGRET it!

I'm totally going down to the poetry slam and doing my own version of that tonight.

Eventually, writer Bill Mantlo started changing the Hulk's status quo around. At one point, Bruce Banner's mind was able to control the Hulk's body, so the Hulk was super-intelligent. But Bruce kept fearing losing control over the Hulk. In one famous scene during Secret Wars, the Hulk holds up an entire mountain that threatens to crush all the heroes, while Bruce angsts about whether he'll be able to stay smart and civilized much longer. At another point, the Hulk lost all vestiges of Bruce and became just a mindless, destructive beast.

Darker gray. For a short while, Bruce stopped being the Hulk, and Rick James became the Hulk for a few minutes. And then writer Al Milgrom turned Bruce back into the Hulk... except that he was gray and smart. And instead of becoming the Hulk when he was angry, Bruce turned into the Hulk when the sun went down. This gray Hulk was craftier than the original gray Hulk, and more corrupt. After he managed to suppress Banner completely for a while, he moved to Vegas and became an enforcer for a casino, under the name Joe Fixit. He totally crushed a takeover bid by the Mafia (referred to as the Maggia for some reason).

Pale green. And then the earlier green babyish persona bounced back. The Hulk went back into therapy (really!) and managed to integrate his three personas: Banner, the gray Hulk and the green Hulk. The resulting Hulk-fusion was a paler green and less brutish than the earlier Hulks. Instead of purple pants, he often wore flip-flops, unfortunately. But the Hulk's rage kept threatening to consume him, so he finally developed a psychological fail-safe where he would turn into Puny Banner if he got too angry. That way, he couldn't hurt anybody. Plus, comedy.

Bright green, again. And then the Hulk went back to being just his regular smart Banner/dumb green Hulk split for a while. But not so much baby talk. And the Hulk seemed to get smarter over time. By the time of Planet Hulk, he's practically a military genius. And a political mastermind.

Red. There's a brand new Hulk, wreaking havoc in Russia and killing old-school foe The Abomination. And it's not Bruce Banner, who's chilling out in General Ross' Gamma Base? Who is the new, redder Hulk? All signs point to longtime sidekick Rick Jones (who actually became a green Hulk for about five minutes in the 1980s). But we'll have to wait and see...

So which Hulk symbolizes romance? Dude, it's all of them. The Hulk is love. 'Nuff said.