Translucent plastic crews

[Raythe]

I have had the good fortune to grab a couple translucent crews, namely Lynch and Pandora's. I have been playing around with the how to deal since I doesn't to do transition from solid paint to the clear parts. 

The issue I'm having is there is no depth of colour and I'm looking to simply wash the clear parts to give them some. I tried just washing the bare plastic (unsurprisingly this did not work at all) after that I tried just using spray sealant and washing over that. It worked alright. I'm just curious what other people have done or seen. 

Thanks in advance for any ideas.