Applying the second color is just as easy as applying the first. We're going to start by duplicating our original black and white image layer and then dragging it over our colorized layer; this lets us keep a better eye on what we're doing now. This next layer is going to be the blue in the flowers. The first thing I'm going to do is look for a picture of blue flowers to sample from (sound familiar?).After sampling the middle tone, then the highlights and dark spots, we'll apply a gradient map, then we'll change the blend mode to overlay and mask only the areas we want colored.You're probably seeing the pattern here. We're going to colorize each object in the picture and colorize it with a Gradient Map using color samples from color photographs.