This guide is for general information only and is not legal advice. Laws change — verify current rules with your state DOT or a licensed attorney before relying on this for any legal matter. Read full disclaimer.
The rule
Michigan requires lamp on the front emitting a white light visible from at least 500 feet to the front. For the rear, red rear reflector visible from 100 to 600 feet when directly in front of lawful low-beam headlamps. a red rear lamp visible from 500 feet may be used in addition to the reflector but does not replace it. The rule applies whenever it is dark. See Mich. Comp. Laws § 257.662.
The cheapest way to stay legal in Michigan is a USB-rechargeable front white light and a rear red light or reflector that meets the spec above. A $30 light set covers it.