Since biological fluids are often semi-translucent, managing opacity is key:

: Apply a subtle Bevel & Emboss layer style to give the edges a three-dimensional, raised appearance. Set the highlight to a bright white and the shadow to a low-opacity cool grey.

Please clarify your goal, and I’ll be glad to help further.

Use a large, soft brush with low opacity to dab hits of cyan, magenta, and pale yellow onto the highlights. Change the Blend Mode to or "Overlay." 4. Refining the Highlights Real liquid has "hot spots." Create a new layer.