the biggest problem i came across when i tried was that they didn't provide an equal amount of the different colors to easily make each strand a different color.
and the first led, and the last led of the strings i had were a special socket, but all the special sockets were of a color.
for example, i had a strand of 150cnt leds from walmart that are c6. the "start" led were red, and the "end" were yellow on each section.
the string of leds have 5 sections of 30 leds. I'd rather get white, then paint them the color i wanted. that was dissapointing this year.