You may have a sticking low oil light sensor. A fresh oil change has cold oil filled in the place where hot oil was. The sensor will them be submerged in this cold oil. If it did not rise again to cut out the light as the oil was added back in the sensor will read low till the oil and sensor heat enough to free back up.

When they drain the oil, change the filter, and then refill with oil, they're supposed to check the oil level AFTER running for a bit and then top off.

Sounds like they put in the 'expected' amount of oil and didn't allow for the oil to fill up the filter.

The red light is low oil pressure, you do not drive it until it has been checked as you will cause serious engine damage.

If you mean the low oil light, then there's not enough oil in it. DO NOT RUN THE CAR! Stop and check the oil before major engine problems happen.

its probably the check engine light