This is a CBS sports article from 3/14/16. This is long before the kneel down protests.

The trade market surrounding Colin Kaepernick is a fascinating thing to watch. The Broncos, Browns and Jets all really need a quarterback.
The 49ers are willing to trade a quarterback. But no two teams can come up with the necessary value needed to make a deal work. Perhaps it's because of the compensation involved? 
Mike Silver of the NFL Network reported Monday the Broncos have told the 49ers they perceive Kap as a fourth-round value.

The Little Guy