The swimming pool here, like all pools, requires a certain amount of maintenance to keep the water clear and sanitary. This means that I have to pop into the local pool supplies shop from time to time, to buy the necessary chemicals.
I spotted this curious accessory for pools in my latest visit - different colour dyes (based on food dyes I guess) to colour the pool water. There are various shades of blue, which means that you could perhaps reproduce the ambiance of a Caribbean holiday. But there are other jolly colour options too: the bright red would allow you to evoke a traditional dolphin slaughter perhaps, and the lurid green could helpfully mask a horrid algal bloom should one occur. Best of all, the yellow ink could allow water aerobic sessions of Incontinents Anonymous to be held in complete discretion. I can't decide if the lack of a brown option is a relief or disappointment.
Apparently the colour fades after a couple of days, and the dye costs a mere 35 euros or so per bottle. A must for any pool owner.