You should be able to reproduce the same effect in Photoshop/gimp/Paintshop ....
In Photoshop open a new image, 1000+1000 pixels for example, choose your fore- and background colours. Apply the background colour to your image, goto Filter/render/ clouds apply the filter, go to Filter/Render/difference clouds and apply it. With ctrl+f apply this filter a couple of times untill you get an effect you like. Play around with Contrast, Brightness and Levels to finetune the map.

Here is a quick test:

You may get other results with your settings and colours, you may select a colour, duplicate to another layer and apply layersettings like emboss to get a lot of different effects, play around it's pure fun! ^_^

Save the final result as .jpg and apply it in D|S to your liquid-surface.

Peter