Good Idea. It should be added.
Awesome idea I would love my barb to look like a red samurai with a katana or a spartan with a curve sword or a Viking with a long sword etc.
The idea of clan colors on the troop itself is an interesting one. However, in order to keep the troop recognizable, it would have to be a pretty small emblem/accessory like a hat or a bag. But if it is that small, you can hardly see it anyway and then the point is what? I don't think any in-between balance can be established, so I'm gonna say this does not really need to happen.
Pop-Up Walls Suggestion: http://forum.supercell.net/showthread.php/169711-Pop-Up-Walls%21-A-unique-trap
Kamikaze Goblin Suggestion: http://forum.supercell.net/showthread.php/160866-Kamikaze-Goblin%21-The-Wallbreaker-Goblin-Hybrid-of-the-Skies
Spell Vacuum Suggestion: http://forum.supercell.net/showthread.php/172122-The-Spell-Vacuum-DE-Lighning-Victims-Have-No-Need-To-Worry%21
This would be very nice, but considering Supercell's lack of significant customizations beyond a clan shield color, I seriously doubt they would take the time to create it. It would require plenty of graphical work designing new images, and supercell does little that doesn't enhance their bottom line bringing in money from gems. No one would buy this if it was something you had to buy with gems, and it's too much work for "free."