However, he is yet to have his underwear inspected in forensic detail by over-zealous officials keen to enforce the tournament's all-white clothing policy.

Wimbledon's insistence on all-white playing gear, a rule stretching back to the 19th century, is strictly observed with only the tiniest amounts of colour allowed on shirts, shorts and dresses.

Read also: New-look Federer breezes in Wimbledon furnace

Federer respects that tradition but is desperate for the tournament not to be too strict.

“It's good fun that it's different but it would be nice to add a splash of colour, let's just be honest for a second here,” said the 36-year-old.

“I understand that traditions are the way they are. I know that Phil Brook, the chairman right now, he believes in strict tradition, going back to the '50s, '60s. 

“I get it. Back in the day, Borg and McEnroe walked out in red outfits. 

“I'm not saying that should happen again. Maybe it would be nice if we mix it up a little bit more.”

That would be great news for Japanese clothing giant Uniqlo with whom he signed a $300 million deal this week, after a career-long relationship with Nike.

“It also creates for the brands a challenge, how much different can you make white. There is ways to do it. They're trying hard, let's put it that way,” he said.

In 2013, Federer fell foul of the rules when his orange-soled shoes were deemed to have broken the code.

However, that was not the worst offence on the famed grass courts.

In 2007, Frenchwoman Tatiana Golovin stunned fans with her red shorts beneath her pristine white dress.

She was allowed to play on as the underwear was shorter than her dress. Golovin's post-match press conference featured 15 questions, 10 of which concerned her flame-red under-garments.

Five-time champion Venus Williams had to change her bra in a rain delay in 2017 as the pink straps were visible on her shoulders.

Three years ago, Canadian star Eugenie Bouchard turned heads by wearing a black bra under her white playing top.

In 2017, a group of boys playing in the junior event had their underwear inspected on court and were told to change.

“The blue and black shorts were our lucky pants,” complained Zsombor Piros of Hungary.

Piros said the white replacements rustled up by tournament officials were very comfortable.

“They never asked for them back,” he added.

At this year's tournament, Australia's John Millman became the latest player to be ensnared by the underwear police when his choice was deemed to be too colourful.

His father had to dash off to a nearby store to find a white pair for his match against Milos Raonic.

“I shouldn't say this, but I have worn those undies, or similar types, for the last few years,” Millman told Australian reporters.

Despite the dramas, seven-time women's champion Serena Williams is a fan of the tradition.

“I love it. I think it's unique. I think against the green grass it's just so pristine,” said the 36-year-old.

“When you're designing, you have to design something that's white, which isn't always easy. It's cool.”