It looks like using the editor to add color to headings is not going to work in the wiki editor. To fix, we need to go into the bbcode view to edit the raw bbcode (the right-most icon in the editor toolbar).
Then, to fix, for example, the first heading "Getting the most out of TB" is currently like this:
Code:
[COLOR=#00ff00][h2][/COLOR][B][COLOR=#00ff00]GETTING THE MOST OUT OF TB[/COLOR][/B][COLOR=#00ff00][/h2][/COLOR]
The editor has put in too many color tags. When fixed to this, it works:
Code:
[B][COLOR=#00ff00][h2]GETTING THE MOST OUT OF TB[/h2][/COLOR][/B]
Note, the bold and color tags come first, then the h2 tag. Exiting each tag is in reverse order (h2, color, then bold).
I will fix what I can when I can, but am pretty busy this week

Sorry for the wonky software
PS - to simplify things, we don't need the bold tags - the h2 h3 etc tags make the font bold by themselves. So this is what a heading should look like ideally:
Code:
[COLOR=#00ff00][h2]GETTING THE MOST OUT OF TB[/h2][/COLOR]