Yellow

Not my favourite colour - it always seems to be either sickly or strident: the latter being the reason why it's used in warning signs. For the same reason, presumably, the early spring flowers tend to be yellow - they attract the attention of pollinators by standing out against winter's mud colours and the grey of a misty, rainy day.

Perhaps it's because of a long cold winter, but this year, our local examples seem to be even more intensely yellow than ever: