For a halloween party i am doing a headless bride cake. I am using red velvet cake,and was think of swirling white cake mix? So when you cut into the cake it appears like blood and bones. I dont ant to use the red syrup for blood.Would the white swirls look bad,what else could i use.

There is a candy that looks like bones. You could bake some of those into the batter. Just an idea - I haven't actually done it.

And if you cant find candy like leah_s suggested, you could make bones out of meringue and bake it in the cake. I havent done this either, tho.

I would consider placing bones inside the cake after baking. Meringue will probably not hold up to the moisture of unbaked cake batter nor the moisture of the cake after it is baked.

When make dacquoise (cake with nutted meringue layers) the meringue gets soft eventually.