Cricket whites were the standard apparel for playing the sport of cricket. They were typically comprised of white trousers, shirts and a pullover knit sweater. The only colour on standard whites was piping around the neck and sometimes waist and wrists of the sweater.
The Doctor's fifth self wore a slightly more colourful version of whites on most occasions. Unsurprisingly, he found these whites near the TARDIS' own cricket club immediately after his fourth regeneration. (TV: Castrovalva)
Perhaps because he knew of the Doctor's personal cricket club, Irving Braxiatel once asserted with certainty that the Seventh Doctor must have had a wide range of whites in the TARDIS. (PROSE: Happy Endings)