The problem with the LED christmas lights are that they are most likely not enough
mcd (candlelight) for what you want. Most likely they are under 5000 mcd's each.
Even the LEDs used for moonlights are typically 6000mcds each.
You would be better buying the proper LEDs and building your own setup. I just
ordered a bulk of the super bright white 10mm LEDs that are 140,000 mcds each
and super bright blue LEDs that are 60,000 mcd's each.