The Nintendo Switch shown in the console's debut trailer is grey. This being Nintendo, though, you can be sure that other shades and variations will be coming.
TheGrumpyCat decided to get out ahead of Nintendo's marketing and mock up a range of Switches. White ones, red ones, there are even Famicom and NES variants, throwback designs that Nintendo often returns to a few years down the line when trying to wring some more cash out of their biggest fans.
Most are pretty nice! But if Nintendo really wants to make some money, they will release that yellow one...
You can see more of the mock-ups here.