I love playing with colors. Funky Coloring is the opposite of what I did in Leave Color tutorial. Here we are going to start with a greyscale pic and color some parts to make it interesting.
Here is a greyscale picture we are going to start with:
Step 1. Selecting
Use the Polygonal Lasso Tool to select the element of the picture you want to color. I selected a flower in Monica's hair.
Polygonal Lasso Tool
Step 2. Layer via Copy
We want to have the selection in the new layer so we can play with it freely. Click on Layer -> New -> Layer via Copy and the selection will copy into a new layer. In my case I got a layer with a flower.
Step 3. Coloring
The most elegant way to color a greyscale object is by using the Photo Filter. Select it by Image -> Adjustments -> Photo Filter.
Choose the color you want and set Density to 100%. I chose green for the first flower.
Now repeat the procedure for other objects. I selected the second flower and colored it blue.
Here is a tip for coloring multiple layers with the same color: select the layers by left clicking on them while holding Ctrl key and then merge them by right click -> Merge Layers. I used that when coloring the bikini which I had to brake into three parts.