As colour had been a strong aesthetic throughout my project, I felt this was the obvious way to go with the guess the time clock. I would use colour as the accuracy indicator. Some way of showing the user how close they had guessed to the real time.
After establishing a structure of what I wanted the object to do, I then needed to find a way to apply it. A Flash animation seemed the simplest option, coding a digital clock face to change colour as the time was entered. As you typed in your guessed time, depending on how close to the real time you were, the digits would turn pinker for earlier or greener for later. So you would know if the digits turned this colour, you had guessed around 15 minutes later than the real time.