That is supposed to be there, however it is supposed to match the color of the crystal you have installed I believe. Mine is white and I have the white crystals. Have you tried installing another color crystal? Is it still pink?
I believe you are talking about the crystal inside the handle, if you look at this screenshot you can see that the artifact actually protrudes out of the handle. It also only appears when the lightsaber is activated; it looks fine when it hangs from my belt.