Personally I Bold Dark Slate Gray (#696969) for Lawful Good. And Navy for Evil but that has something to do with often being a blue dragon which talks LIKE THIS.
Oh yes, the actual point of this thread.
Loyal Paladin's Solar Bow
Transmutation
Level: Sanctified 9
Components: S, V, Sacrifice
Casting Time: 1 Standard.
Range: Touch.
Target: Bow touched.
Duration: 10 minutes/caster level.
Saving Throw: Will negates (harmless, object)
Spell Resistance: Yes (harmless, object)
When you cast this spell you imbue the touched bow (not crossbow) with the mighty power of a Solar's weapon. The touched weapon gains a +2 enhancement bonus and any arrow fired from it functions as a slaying arrow of the chosen type (DC remains 20).
Sacrifice: When this spell is cast the caster suffers 2 points of Constitution burn.