I've always understood Captain America to only have one shield, as it's made of the incredibly rare vibranium alloy.
In Captain America: The Winter Soldier, during the battle aboard the Lemurian Star, his shield appears to be colored differently. Rings 1 and 3 (outward-in) appear to be blue-gray, while ring 2 appears to be a reddish-gray.
However, later in the film, when Cap is fighting The Winter Soldier, the shield has the more traditional colors.
At first, I thought it may be a trick of lighting, but the skin tones in the Lemurian Star fight scene are all normal, despite all the movement across the deck. The color difference is local to the shield.
Additionally, in the scene where The Winter Soldier catches Cap's shield during their fight at night, the shield has its normal colors.
Does Captain America have more than one shield? If so, where did the new shield(s) come from?
For consideration: out-of-universe, it is specifically a physically different shield, not just a trick of lighting.