I know a lot of you guys use Sunburst yellow, but its too bright to be accurate to the original paint.
I think we've been around about this a dozen times on this board.
What original paint? Siren manufacturers didn't all use the same exact paint.
The old late 50s Thunderbolts I've had had original paint that was very close to the sunburst yellow. As I was sanding the old paint off the paint underneath was almost identical to SB yellow. Yes the later model Thunderbolts had a darker yellow. The 2t22 I restored had paint that was very close to the SB yellow too. The old square horn Sentry that was in Allen had a very bright yellow paint on it. There was never an official civil defense yellow color that I know of.