Clip-in extensions: pick up coloured extensions from fancy dress shops, Ebay or buy blonde extensions and dye them (with your colour of choice). Coloured extensions are also stocked at some hairdressers or wig shops. This is a good approach to take if you have hair that is in poor condition (you don't want to stress it out with more colour, even if temporary) or if it will be a hot and sticky environment and you don't want 'your colour to run!'.
Spray In Colour: I'm talking about those little spray cans of colour you may have excitedly purchased in your school days to experiment with colour in the only way you could without your parents having a heart attack. These are the kind of colours that wash out straight away. Try Stargazers Colour Spray in pink (which you can buy via Amazon) or search in your local dress-up shop for coloured sprays. To do this properly, first pop on some rubber gloves, and make sure you're not near walls - just in case that wasn't obvious... Cover the floor around you in some old towels or newspaper. Use another towel and place around your shoulders and have it styled by this stage (it will be a disaster if you try to curl your hair after doing this activity). Start by sectioning the hair in half and bring it around to the front and leave the strands flat against your shoulders, then spray colour onto the ends. Voilà!