Legality of clear indicators ? UK

[sfj642]

In the UK and I think in the USA we must show orange flashing for our indicators. The current craze seems to be to fit clear holders with orange or silvered orange bulbs.

I've just tried out one front one on my Compact - a clear lens with orange bulb - visually great. But compared to the stock one on the other side, flashing visibility in daylight seems to be much reduced, although it is not too bad at night.

In daylight, instead of the whole area of the orange lighting up as the stock indicator, I only see a bright orange bulb shining through a clear lens. Visibility seems to be much reduced.

The point is this - as the car is modified and under certain conditions at least, the turn signals are less visible - is the car still legal and should my Insurance Company be informed of the modification from stock ?

Thanks