Love the Tumbler - probably my favorite build so far. In addition to the black one I wanted a white one - but due to the brick color contraints I decided to go with 'Light Blueish Gray'. There are certainly a few gotchas, but I like it anyway :)
As you can see - the plaque has been a bit photoshopped to be gray-ish as well.. Finding the minigure parts was fun too
There were a few tricky bits that simply weren't available in Light Bluish Gray, like the bar holders, so I had to 'flip' them.
And those ones
The side was tricky as the slope part simply doesn't exist in Light Bluish so I had to build something similar - which I think is good enough.
Another slope issue - but that was easily fixed as well
The flags in Light Bluish took weeks to find
I really wanted to find everything in Light Bluish so I even changed things like those pedals
For the display I also had to come up with something as I have the bike too - so build a little stand with the spare tumbler pieces
So it is slightly higher than the Tumblers