A question I am often asked is what can coloured cable ties be used for? Personally, I have found a large variety of uses for coloured cable ties.
Using various colours of cable tie is a great way to quickly identify a bundle of wires. If you are adding a new network to a building you could group cables by room or by server.
Silver cable ties are ideal for attaching your car hubcaps to their wheels. I would say silver works best because they blend with the colour of the hubcap leaving very little evidence that a cable tie is holding them on. However, if you were to do this, you need to have a pair of cutters with you to remove the ties for access to the wheel in the case of a puncture.
Red cable ties can be used to tie the comic relief red nose to the radiator grill of your car.
Green and brown cable ties are ideal to use in the garden when you want to disguise the tie in among the foliage, or securing rabbit guards to the base of young trees to protect them from hungry rabbits.
Blue is seen as an intrinsically safe colour and so blue cable ties can be used in situ with anything deemed to be safe, such as the hand sanitary gel bottles found in hospitals.