Working with Black-and-White and Color Images - GIMP 2.6 for Photographers: Image Editing with Open Source Software - page 343

The next layer is the portrait clothes layer:
• Duplicate the portrait-colored layer.
• Give it the name portrait-clothes .
• Position it above the portrait-hair layer in the Layers dialog. Choose Colors
> Levels and move the mid-tones slider to lighten the clothes. Then use
the blue channel to apply dark blue color to the clothes and set the mid-
tones for the channel.
• Use the Fuzzy Select tool (Magic Wand) to select the visible area of the
clothes, and then use the Free Select tool (Lasso) to correct the holes in
the selection. ( Note : The back of the chair shows behind the left shoulder.
The visible part extends from the top of the image to the hair curls on the
shoulder.)
• Choose Select > Feather and set it to 8 pixels.
• Choose Select > Invert .
• Choose Edit > Clear to delete everything except the clothes.
• Then choose Select > None to close the selection.
• Finally, select Colors > Levels to correct the contrast and brightness.
Now create the portrait-face layer:
• Duplicate the portrait-colored layer.
• Rename the layer portrait-face .
• Position it above the portrait-clothes layer in the Layers dialog.
• Use the Fuzzy Select tool to select the face. Use the Free Select tool (Lasso)
to remove areas from the selection, which were not supposed to be
selected.
• Choose Select > Feather and set it to 20 pixels. Choose Select > Invert .
• Delete all other contents except the face with the Edit > Clear menu item.
• Choose the Select > None menu item.
• Access the Colors > Levels menu and use the red and green channels,
modifying the mid-tones, to color the face.
• Then choose Colors > Brightness-Contrast to correct or reduce the contrast
and brightness.