I did a few 4" Ring Its for a buddy this morning using motor oil over fluorescent orange and motor oil over a thin amber. The colors turned out super nice, so I did a few for my own use and then did a few in this minnow bait.

The plastic is Essential and the colors are all X2 colors. The orange has some gold hi lite and gold .015 glitter. The amber got some black .015 glitter with just a touch of gold hi lite. The motor oil has no flake in it but it does have a hefty shot of Do-It bronze hi lite.
The strong sun today really pulls the green out of the motor oil. In the shade of the garage interior the brown pops right out at ya. Motor oil is a really interesting color to work with because of the color change it has going on. Once this fair stuff is over I plan to put these to the test on the river.