While I don't expect Honda to go to such lengths as disguise the throttle bodies as dummy carbs like Triumph does on the Bonneville, I wish they had made their TB a little more aesthetically pleasing. That round spot looks like they left off something. My eye always goes to that spot, even if just for a second.
I did a half-hearted search for some sort of false button I could affix there. A red button with the word "NO!" or "EJECT" would be fun. Maybe an arcade console button would work, but no clue if it's the right size.
Last night while fiddling around in the garage, I looked at the round blank and and realized it's about the size of a quarter. Grabbed my pocket change and sure enough, a quarter fits perfectly. So, I thought about which quarter I might use. Thought about my birth year, the bike's model year, and even 1969 for the first year of the CB750. Then, I decided to use my home state's quarter. It fits pretty snug on its own, but a dab of clear rtv silicone ought to hold it.
I think it looks pretty cool: