The required effects is that of a changing color light bulb. It would preferably be an emission mesh.
You can do this by giving your object a material, and in that material, using a Value Node with
#frame as a value, connected to the hue modulation of a Hue/Saturation/Value Node.
When you enter
#frame into the value node, it will change color and change to 1.0 - this is normal, it will change along with your frame when you animate. I find the default rate of change too fast, so I usually multiply it by some low value to slow it down. When you connect it to the HSV Node, you must also input SOME color (default white will not work). I used an RGB Input node so I can easily change the "base color". Connect this to an emission shader, and then to the material output. When you press "play" the color will change with the frame number.