Please see below details of clothing rules for competion from the UKA rulebook…
RULE 17 CLOTHING
(1) In all events competitors must wear at least vest and shorts (or equivalent clothing) which are clean and so designed and worn as not to be objectionable, even if wet.
(2) In team or relay races all competitors must wear registered vests of the same design and colour of the team they are representing, unless the Referee has given permission for a change to be made.
NOTE 1: This Rule does not preclude the possibility of clothing being different in style between participants in the same team e.g. vests of different length, cut of sleeve or collar etc. Any team clothing should, though, still broadly correspond in colour and design notwithstanding these differences.
NOTE 2: Clubs are permitted to have two sets of colours registered at any one time. In team or relay races all competitors should wear registered vests of the same design.
(3) In individual English County, Scottish District, Welsh Regional and National Championships, (but excluding Road Running) athletes must wear the vest of their first-claim affiliated Club, their County or National vest, or any other Representative vest approved by UKA. The affiliated Club concerned must be the one which in terms of Rule 2
(4) caters for that particular discipline of athletics.
RULES 16, 17 18 NOTE: In exceptional circumstances the Referee may grant permission for an alternative vest to be worn.
(4) Except as is allowed for in Rule 16, competitors are not allowed to take into an arena or course any form of advertising material, nor to display on their person any such advertising other than:
(a) the accepted name of their affiliated Club in lettering which should not exceed 4cm in height. In the case of County vests the lettering indicating the name shall not exceed 6cm in height.
(b) a single Trade Mark of the manufacturer of the clothing they are wearing which may appear on the upper body attire. This Mark must not exceed 20 square cm, with the lettering maximum height of 4cm and the total logo maximum height of 5cm. On lower body attire the logo shall not exceed 20 square cm with maximum height of 4cm and may only appear once.