Several hour later Minlog has got font-lock support now. The result speaks for itself (left without font-lock, right colored, and below a complex formula nicely painted in colors):

Need some recovery from regular expressions now. When I look outside the window I only see the \\(green with \\(?:tree\\)+ and \\(blue\\|dark\\) sky\\), tonight I will dream of horrible monsters like ^\\(?:>[ \t]+\\)*;\\(?:[ \t]+\\?[^ \t:\n]*\\| \\{3,\\}[^\t:\n]+\\):[ \t]*. Did I already say that multiline font-lock keywords are evil?