For the highlights of the tail color ( #A7D3E0 ), you’ll want a lighter or more vibrant color to create a shimmering effect that captures the light:

 <Angler Fish Tail Highlight>
1. Frosted Sky - 
                            
                            #B0E0E6
                         - A light, frosty blue that adds a soft highlight, simulating the reflection of light on the tail.

This Frosted Sky highlight will provide a nice contrast against the Bioluminescent Blue of the tail, enhancing the visual appeal and giving it a lively, cartoonish look.

Would you like to see how these colors work together in a specific design, or do you have any other elements you want to explore further?