I had my lower arm done by Dan Henk about 5-6 years ago? although lacking outlines, the color is still incredibly bright and I get compliments constantly on that alone. Of course, I did go to someone who knew what he was doing and on top of that, they are two skeletons wearing draped robes and the tattoo only has black and grey, blue and green. I am sure the minimal use of color helps a lot.
That being said, it is the one and only tattoo I have lacking outlines and will remain so.