As long as they meet the MOT regs they should be legal
Direction indicators must emit amber light, except motorcycles first used before 1 September 1965 can have white front indicators and red rear indicators.
A ‘light source’ means any bulb, LED or other means of emitting light.
You must assess damaged or repaired lamps for security, colour, light output and durability.
Direction indicators that function sequentially/dynamically are not to be considered a reason to fail.
Defect Category
(a) A direction indicator:
(i) lamp with a multiple light source up to 1/2 not functioning
(ii) lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning
Minor
Major
(b) A lens defective:
(i) which has no effect on emitted light
(ii) such that the emitted light is adversely affected
Minor
Major
(c) A lamp:
(i) not securely attached
(ii) likely to become detached
Minor
Major
4.4.2. Switching
Check that the director indicator switch is secure, can be used from the normal riding position, and works as intended.
Defect Category
(a) Indicator switch:
(i) does not operate in accordance with the requirements
(ii) inoperative
Minor
Major
4.4.3. Compliance with requirements
You must inspect all direction indicators fitted.
Direction indicators must emit an amber light, except motorcycles first used before 1 September 1965 can have white front indicators and red rear indicators.
Switch on the direction indicators and operate all the other lamps in turn to see if the direction indicators are adversely affected.
The position lamp on the same side of the direction indicator may or may not switch off when the indicator is switched on.
Some motorcycles have direction indicators combined with the position lamps. In these cases the position lamp does not have to switch off when the relevant direction indicator is switched on.
The precise position of direction indicators are not part of this inspection, but they must be on each side of the longitudinal axis of a solo machine. If a sidecar is attached, the indicators must be on opposite sides of the combination.
Mandatory direction indicators must have minimum separation distances between the illuminating surfaces of:
mopeds (Category L1) - 240mm at the front and 160mm at the rear
solo motorcycles - 240mm at the front and 180mm at the rear
motorcycle and sidecar - 400mm at both front and rear
There is no requirement to measure the separation distance and they should only be rejected if the separation distance is obviously incorrect.
You must assess damaged or repaired lamps for security, colour, light output and durability.
Direction indicators that function sequentially/dynamically are not to be considered a reason to fail.
Defect Category
(a) Lamp emitted colour, position or intensity not in accordance with the requirements Major
(b) A direction indicator lamp adversely affected by the operation of any other lamp Major
4.4.4. Flashing frequency
Indicators must flash between 60 and 120 times per minute.
Defect Category
(a) Rate of flashing not between 60 and 120 times per minute Minor