Azmalious's Draconic Ember

You extend a hand in the direction of your opponent, sending a beam of flame with a dragon figurehead hurtling toward them. If the flames strike true, the target takes 4d10 fire damage. If the target is a Dragon, add an extra 2d12 fire damage. If the dragon is resistant to fire, the extra damage changes to force. The color of this spell can be changed from normal flame to any color if you add a component that would reasonably dye it. Blue dye makes it blue, a rose would make it red, an emerald would make it green, ect.

At higher level:

If you cast this as a level 9 spell, the damage becomes 5d12 damage, and the extra damage is 3d12. You can also change it's color without components, even making it multi-color for a little bit of razzle dazzle.