I'm sure it is illegal as part of the new regulation. The color is legally reserved for a particular car mode. Likewise, you can't have bright red lights that

I'm sure it is illegal as part of the new regulation. The color is legally reserved for a particular car mode. Likewise, you can't have bright red lights that turn on-and-off when you're not braking because that light behavior is legal but reserved for the braking mode.) (It's true that this will be more difficult to enforce than prohibitions against using darker blue, since a regular passenger car using them is clearly a violation, whereas pulling someone over for the light blue will presumably require the officer to have probable cause that the car is not self-driving.)