Changing of Lanes

My question involves a traffic ticket from the state of: colorado i was charged for violating 42-4-903, the officer said i used my signal but for the 100 ft rule. Well 42-4-1007 does not state 100 ft. Also in 42-4-1010 stages , traffic so merginging shall be subject to the RULE GOVERING THE CHANGING OF LANES AS SET FORTH IN 42-4-1007 1(a). So how is that im charged for violating 42-4-903, i see the 100ft rule as for intention for making a turn, in fact i was making a lane change and i used my signal.

Changing of Lanes