Hmm on both wikis (on the articles I checked) the color of the headings is the same as the color of the paragraph text, and the color of the "edit" links is the same as the color of all links on that wiki. Those colors can be defined by admins on the Theme Designer.
Okay, if you want different colors for the header than the other text (and you are an admin), you can use CSS for that. Would you want to link the wiki you want to do that on and tell what colors you want?