I just got an idea of taping mini glowsticks to the spark but i'm wondering how visiable they'll be at night from a higher altitude.

I was thinking of maybe something like these..

Hi, sir. We would not recommend users attach accessories on the drone. Please fly in a place with sufficient light.

The LEDs under each motor are pretty bright at night.  I doubt faint glow sticks would show up very well in comparison.    Now if they made Spark props with internal rechargeable LED's like they have for model RC helicopter rotor blades, we would have something.

At Halloween, I hung a paper skeleton on a 40 foot string and attached glow sticks to the skeleton. I flew it around a wide open field across from the church parking lot where trunk or treat was held, went over pretty big.