CTRL+Click on the layer will select the item on the layer.

Then you can fill it.

Also you can create Solid color adjustment layer, and either group it with previous layer to fill the item or select the item and ALT click on Solid color layer mask and fill it with black. Then invert the mask, that way you can have multiple layers colored with same color leaving others alone and another advantage is that you can change the color whenever you want :)

There is just about another mill. of ways to fill the item, but this are most common IMHO :)

Ok I was just look at what you need exactly, for that its better to use Channel mixer and set to monochrome, then you have much more power to get exact black and white contrast that you want :)

Tihomir

Open your mind and share the knowledge!