Captain Packers
Not a 100% answer but you may want to try the following.
I presume you cant open it with a click, can you change the colour to a known colour number not used by anything else?
It may be possible to search for that color name in the text of you wiki file opened in an editor, give it a better name and return to the wiki to delete it.
All it needs to exist is some tag field with some non space characters in it, by mistake. You could simply ignore it if you can't find the tiddler.
Perhaps it has a caption set?
Look under the tags menu in the side bar to see if you can find it,
If you do not have many tiddlers or tags search/list for all tiddlers with a non blank tags field and check each one to find which is responcible.
Regards
Tony