My game will not start with ivtoolkit in the mods folder. It just reverts back to the play button on the launcher while I wait for it to launch the game. It always says this:

[20:00:23] [main/INFO] [LaunchWrapper]: Loading tweak class name

[20:00:23] [main/ERROR] [FML]: An error occurred trying to configure the minecraft home at C:\Users\Bella\AppData\Roaming.minecraft for Forge Mod Loader
java.lang.UnsupportedClassVersionError: ivorius/ivtoolkit/IvToolkitLoadingPlugin : Unsupported major.minor version 51.0

What does this mean?

Psychedelicraft requires Java 7+ to work. I've written a tutorial on switching to it here: http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-tools/2167922-jre-list-tool-switching-to-java-7-on-osx
:)