Photoshop’s ability to adjust the colours in an image is well known. But did you ever wonder what you would do if you didn’t get the settings right first time?
Trace around the outline of your subject, using any of the selection tools. Click the Refine Selection button and increase the Smooth value.
Click the Hue/Saturation icon in the Adjustments palette. Use the Targeted Adjustment icon (the pointing hand) and Cmd/Ctrl-drag on the hood until the majority of the subject changes colour.
Go to Select>Reselect and then use Select>Inverse to switch to the background area. Click on the Black & White adjustment to remove any colour from here.
Add another adjustment layer, this time for Levels, and slide the central handle far to the right. Click on the layer mask thumbnail and add a radial black gradient to the mask.