Re: Venturi3d example
whether something is colored blue, red or whatever depends probably on your post-processing software and is not directly related to OpenLB.
I suppose that by “blue” you mean material number 1. The design of OpenLB strictly requires material number of 1 for fluid cells and other for boundaries. That means you better DO NOT change your material number in OpenLB, but adjust your color mapping to get ‘your color’ in your post-processing software.