well  , their website says 1.5 parts paint to 1 part thinner for airbrush .

Man  , that seems like a lot .

That stuff must be really viscous .

well . EDIT  ,  the one page suggests 1.5 to 1 but this product page is back to the 3 or 4 parts to one part thinner :

[URL unfurl="true"]https://www.revell.com/products/colors-accessories/accessories/aqua-color-mix-100ml.html[/URL]