During Skyrise a battery source of power for LED light strips was not allowed by rule R13 (comparable to Turning Point R14). Obviously old Q&As don't directly apply to new games, but they often do provide insight into what has been allowed/disallowed in the past.
https://www.vexforum.com/index.php/13041-answered-led-lights-for-decoration/0
In light (no pun intended) of the recent Q&A answer https://www.robotevents.com/VRC/2018-2019/QA/162 where LED lights are powered by a battery that isn't a V5 or Cortex battery...
Can a robot have LED lights powered by an external battery source (not Cortex or V5 battery) providing R8 isn't violated? or is it only small self contained objects that are allowed (that don't include external wiring)?
<R14> The only allowable source(s) of electrical power are as follows: a. If using a VEX ARM® Cortex®-based Microcontroller, robots may use (1) VEX 7.2V Robot Battery Pack of any type, and one (1) 9V backup battery. i. Robots utilizing the VEX Power Expander may use a second VEX 7.2V Robot Battery of any type.
b. If using a V5 Robot Brain, robots may use (1) V5 Robot Battery (276-4811).
<R8> Teams may add non-functional decorations, provided that they do not affect the robot performance in any significant way or affect the outcome of the match. g. Decorations that visually mimic field elements or could otherwise interfere with an opponent’s Vision Sensor are considered functional and are not permitted. This includes lights, such as the VEX Flashlight.