When it rains you can purchase A poncho or a umbrella at usually all in door merchandise locations. The umbrella is a basic Disney Parks Umbrella with Mickey Mouse and the castle on it it retails for 10 dollars plus tax.
the ponchos are like $7, but it's actually sturdy plastic. I got one from Universal once and it was only $3, I was amazed at how cheap they were, until they ripped, very easily. Very cheap plastic. So it's actually worth the extra money, you're getting quality.
There are kids sizes as well as adults and it s a basic poncho. It is clear plastic with a big Mickey On the back with the Cinderella castle as a sillhouette behind him below it in BLUE says Disney Parks and below that it lists all the parks, Anaheim, Orlando, Disneyland Paris, Hongkong, Tokyo. They are good overall and do the essential function they were designed to do.
We bought these in Oct when it was raining, the cost was $8 (they used to be free but not anymore) and you can find them at most of the stores and Kiosks in the park while supplies last, they also have umbrellas. As the above poster stated, they are clear and I just also wanted to add they snap at both sides and have a hood. The hood doesn't quite stay on and slips back (but not off) so if you are concerned with keeping your head dry I would wear a hat with these.