I tick like a clock,
But the hands are red and yellow for some reason.
When I alarm, I wave my hands pretty fast,
And when I notice when its midnight, both hands put down to 6.
Is the answer
Semaphore flags are red and yellow and are held in one’s hands.
Waving the flags is the code for “Attention”, or alarm.
Both flags down signifies the end of a word, like how midnight is the end of the day?
Not sure what the ticking means, but everything else seems to fit well enough.