The lack of red in Britain's Stella McCartney-designed official team kit for the London Olympics could leave some athletes feeling blue, as well as irritating the Welsh.
University professor and sports psychologist Robert Barton, co-author of a 2005 report that demonstrated how athletes performed better in red colours, feared the predominance of blue could backfire.
"Given the effects that we and other scientists have found, it does seem like a mistake," the Durham University academic told the Guardian newspaper on Friday.
England won the 1966 World Cup in red shirts and socks, their sole success in the tournament, while 'Red Devils' Manchester United and 'Mighty Reds' Liverpool have also been hugely successful in that colour.
Previous British Olympic kits have seen more red featured along with the other colours of the Union flag, white and blue.
The newspaper also quoted clinical sports psychologist Victor Thompson as saying the designer "may have missed an opportunity" to include more red in the design.
"For instance if the red increased confidence, aggression and sense that they (the athletes) are dominant, then they are likely to perform closer to their peak performance potential."
The adidas kit was revealed at the Tower of London on Thursday with leading medal prospects parading in front of the cameras.
McCartney reconstructed Britain's flag in shades of blue, with red trimming around the neck. The shoes and knee-high socks worn by triple jumper Phillips Idowu were also red.
The design disappointed Welsh politician Jonathan Edwards of the Plaid Cymru party.
"Red is of course the colour of Welsh sport and, as demonstrated by our fantastic Grand Slam-winning (rugby) team last weekend, also the colour of victory," he told the Daily Mail newspaper.
"Having said that, it is more about performance than appearance and the athletes' success will be down to dedication and tireless training and not what they're wearing."
Britain is sending its biggest-ever team to the July 27-Aug. 12 Games in London, the first city to host the Olympics on three occasions, with a squad of more than 550 athletes.
The country finished fourth in the medals table in Beijing in 2008 with 47 from 11 sports, including 19 golds.