Ryan hypothesizes that darker colors heat up faster. he places a thermometer inside a red wool sock, a green cotton glove, and a black nylon hat. whats wrong with his procedure

There's no "control" they all differ. If they were all exactly the same size shape and material it would be doable.

There is no light/heat source to allow for the warming up of the materials and he didn't take an initial temperature. If he were to place the sock, the glove, and the hat out in the sun, or even under something as simple as a lamp (but it has to be directly underneath), he'd notice that when he places the thermometer within the items, the black hat warms up faster since dark colors absorb light/heat.