Skulls sketchs for tattoo

While I can see that the different colors on the linework are just to help you when making the final linework, I really think they add a nice touch to the drawing. The contrast between the red skull and the blue beard on the right is fantastic, It really makes a simple oldschool skull tattoo feel so much more alive. I'm really curious to see if you'll be able to add this same feel to the tattoo itself, maybe with softer lines and coloring.
I think both skulls are great, the right one looks more finished, but I can see the same potential in the left one.