Royal orange was a bright shade of orange.
The Sixth Doctor wore royal orange spats with his forest green ankle boots. (TV: The Twin Dilemma-Time and the Rani) His successor, the Seventh Doctor, wore them in his first hours before switching for white and brown spectator shoes. (TV: Time and the Rani)
The Fifteenth Doctor wore a royal orange tank top when he met Ruby Sunday. (TV: The Church on Ruby Road)