why does leaving something out in the sun cause it to fade?

When you leave sports equipment outside on a sunny day, have you noticed that the colour fades? have you ever wondered why? well that's what our class is finding out!

Yesterday afternoon, we put different kinds of  fabric in the sun and we are experimenting to see which ones will fade the fastest. Here are some questions we have:

•  Will they all get the same amount of sunlight?
• Will the different colours affect the fading? 
• will the kind of fabric affect the fading speed?

                                       Here are photos of our experiment and a faded photo:

These are the videos we watched about how colour fading works