here we check all palette rules like "api has-curl" or "messages-module messages-internals" start from the root, make dfs expanding next_with_colors and check all rules for each dfs chain these chains are left-to-right, e.g. colored f1->f2->f3, we find and check f1, then f1->f2, then f1->f2->f3
source not stored for this graph (policy: none)