Want to add one more fish
 

I have a 72 gallon FOWLR 40lbs of LR, one yellow tang, one maroon clown, one coral beauty and one bird wrasse. What would you recommend for a final fish that is bright and attractive?
Someone suggested a dwarf lion fish but I wanted something more colorful like a dottyback. I just want to make sure they are not all disturbed by the new arrival.

An Arabian Psuedochromis, Flame Hawk, Sharpnose Puffer, Royal Gramma, Yellowtail Fang Blenny, Sixline Wrasse, or a Purple Square Anthias are some of the fish that come to mind when trying to find something hardy, colorful and compatible with the list of fish you mention.

Good Luck,
Ed

I agree with Ed 100%.
Considering the size of your tank and the activity of the fish you already have, any of these would be happier as well, with the lion preferring a quieter, mellower and more laid back tank to do well.