user27380: Yesterday, I was in a clothes shop and saw shirts that had wild patterns with screamingly bold colours.
The same day, I saw this picture from the Angolan Chess Olympiad team, whose shirts reminded me of those I had seen earlier that day.
I wondered whether it could be considered a distraction if they had the same flashy colours as the shirts I had seen earlier.
If the colours are so flashy, that it's hard to ignore them and the patterns make you dizzy when seeing them (maybe from the corner of your eyes), would it in theory be possible to claim a distraction?
What would you do, and what would happen to the opponent if he had no clothes to change?

user4418: 
would it in theory be possible to claim a distraction?

Of course you can claim whatever you like however your claim will be dismissed if it is just the colour scheme of your opponent's clothes. To count as "distracting" they would either have to depict nudity, semi-nudity or expose flesh in a way that would be considered distracting.
FIDE does have a dress code for FIDE events. These events include Olympiads, World Championships, Candidates, qualifiers, etc. They do not include lower level FIDE rated events although arbiters and organisers are likely to use them anyway as guidelines.
Here is an extract from the above linked document -

3. Dress Code for players during games in progress.
3.a. The following is acceptable for men players, captains, head of delegation.
Suits, ties, dressy pants, trousers, jeans, long-sleeve or shirt-sleeve dress
shirt, dress shirt, alternatively T-shirts or polo, dress shoes, loafers or
dressy slip-ons, socks, shoes or sneakers, sport coat, blazer,, Bermuda
shorts, turtleneck, jacket, vest or sweater. Team uniforms and
national costumes clothing.
3.b. The following is NOT acceptable for men players, captains, head of
delegation.
Beach-wear slips, profanity and nude or semi-nude
pictures printed on shirts, torn pants or jeans. holes, denim shorts,
short-shorts, cut-off shorts, gym shorts, unclean clothing, sun glasses,
sport caps.
3.c. The following is acceptable for women players
Women's suits, dresses. skirts, blouses, turtleneck, T-shirts or poloʼs,
trousers, jeans or slacks, footwear (boots, flats, mid-heel or high-
heel shoes, sneakers with sock), jacket, vest or sweater, a scarf, as
well as jewelry (earrings, necklace, etc.) coordinated to the outfit
may be worn. Team uniforms, national costumes clothing.
3.d. The following is NOT acceptable for women players
Beach-wear slips, profanity and nude or semi-nude
pictures printed on shirts, torn pants or jeans. holes, noticeable
unclean clothing, sun glasses, sport caps. Revealing attire. Clothes
such as denim shorts, short-shorts, cut-off shorts, gym shorts, crop
tops, tank tops, and clothes made of see-through materials or
clothes that expose areas of the body usually covered in the location
where the event is taking place.

Note that team uniforms and national costumes are explicitly allowed. Hence the Angolan brightly coloured uniforms are explicitly allowed.

what would happen to the opponent if he had no clothes to change?

The player with the offending clothing would have to either go back to their hotel and change or go out and buy suitable clothes. This has happened in a World Cup to an over-casually dressed Canadian player and the player ended up flying home early.

27380: <p>Yesterday, I was in a clothes shop and saw shirts that had wild patterns with screamingly bold colours.
The same day, I saw this <a href="https://www.facebook.com/chess/photos/a.395509529570/10160349828169571/" rel="nofollow noreferrer">picture from the Angolan Chess Olympiad team</a>, whose shirts reminded me of those I had seen earlier that day.
I wondered whether it could be considered a distraction if they had the same flashy colours as the shirts I had seen earlier.</p>
<p>If the colours are so flashy, that it's hard to ignore them and the patterns make you dizzy when seeing them (maybe from the corner of your eyes), would it in theory be possible to claim a distraction?
What would you do, and what would happen to the opponent if he had no clothes to change?</p>
 4418: <blockquote>
<p>would it in theory be possible to claim a distraction?</p>
</blockquote>
<p>Of course you can claim whatever you like however your claim will be dismissed if it is just the colour scheme of your opponent's clothes. To count as &quot;distracting&quot; they would either have to depict nudity, semi-nudity or expose flesh in a way that would be considered distracting.</p>
<p>FIDE <em>does</em> have a <a href="https://www.fide.com/images/stories/NEWS_2013/FIDE/Proposal_of_Ms._B._Marinello_in_respect_of_the_dress_code.pdf" rel="noreferrer">dress code for FIDE events</a>. These events include Olympiads, World Championships, Candidates, qualifiers, etc. They do not include lower level FIDE rated events although arbiters and organisers are likely to use them anyway as guidelines.</p>
<p>Here is an extract from the above linked document -</p>
<blockquote>
<p><strong>3. Dress Code for players during games in progress</strong>.<br />
<strong>3.a. The following is acceptable for men players, captains, head of delegation</strong>.<br />
Suits, ties, dressy pants, trousers, jeans, long-sleeve or shirt-sleeve dress
shirt, dress shirt, alternatively T-shirts or polo, dress shoes, loafers or
dressy slip-ons, socks, shoes or sneakers, sport coat, blazer,, Bermuda
shorts, turtleneck, jacket, vest or sweater. Team uniforms and
national costumes clothing.<br />
<strong>3.b. The following is NOT acceptable for men players, captains, head of
delegation</strong>.<br />
Beach-wear slips, profanity and nude or semi-nude
pictures printed on shirts, torn pants or jeans. holes, denim shorts,
short-shorts, cut-off shorts, gym shorts, unclean clothing, sun glasses,
sport caps.<br />
<strong>3.c. The following is acceptable for women players</strong><br />
Women's suits, dresses. skirts, blouses, turtleneck, T-shirts or poloʼs,
trousers, jeans or slacks, footwear (boots, flats, mid-heel or high-
heel shoes, sneakers with sock), jacket, vest or sweater, a scarf, as
well as jewelry (earrings, necklace, etc.) coordinated to the outfit
may be worn. Team uniforms, national costumes clothing.<br />
<strong>3.d. The following is NOT acceptable for women players</strong><br />
Beach-wear slips, profanity and nude or semi-nude
pictures printed on shirts, torn pants or jeans. holes, noticeable
unclean clothing, sun glasses, sport caps. Revealing attire. Clothes
such as denim shorts, short-shorts, cut-off shorts, gym shorts, crop
tops, tank tops, and clothes made of see-through materials or
clothes that expose areas of the body usually covered in the location
where the event is taking place.</p>
</blockquote>
<p>Note that team uniforms and national costumes are explicitly allowed. Hence the Angolan brightly coloured uniforms are explicitly allowed.</p>
<blockquote>
<p>what would happen to the opponent if he had no clothes to change?</p>
</blockquote>
<p>The player with the offending clothing would have to either go back to their hotel and change or go out and buy suitable clothes. This has <a href="https://www.chess.com/news/view/dress-code-incident-at-world-cup-kovalyov-forfeits" rel="noreferrer">happened in a World Cup</a> to an over-casually dressed Canadian player and the player ended up flying home early.</p>
