I'm helping my daughter with a science project. We're designing a glove for crossing guards with red and green LEDs attached. I thought it would be a good idea to put a small button in the thumb area that when pressed would turn off the green LEDs and turn on the red LEDs. Then when released the reds turn off and the greens turn back on. Here are the LEDs we're thinking of trying: String LEDs
Looks like I'll need to cut the battery pack and wire the switch/button in between. Where I'm struggling is what kind of button to use (SPDT/DPDT) and how to wire it.
Also, could I hack the battery pack and combine the wiring to make a master on/off switch that controlled them both?