I frequently carry around a set of slimPAR38 LED spotlights. I use these as a contingency for events where the lighting falls short of what is necessary for good coverage.
One example is a Year 6 Prom I covered where lighting was not provided for a surfboard simulator. Without the PAR cans the only other lighting option would have been the venue’s main fluorescent lighting, which would have seriously compromised the atmosphere (and accompanying disco!)
Another example was a music event where the main lighting bar was obstructed by decorations, meaning that the performers faces were in relative darkness. I was able to use the PAR cans as uplighters at the side of the stage, which dramatically improved the lighting.
The lights are typically set to slowly fade through the colour spectrum but can also be configured to provide static lighting.
These lights have made otherwise un-photographable events possible, with very little overhead. They are easy to set up and adaptable for any event, either to provide direct lighting or simply to add atmosphere.