Red Coloring ft. Danny Jones (GIMP and Photoshop)
How to go from 
to
using either The GIMP or Photoshop CS5.
Difficulty: Easy
Translatable: Yes, no selective coloring.
Other example:
First, take your base. I got mine from dont_be_so_base.
Add a new layer and fill it with 5c0000 (or if working in CS5--or any version of photoshop--just click new fill layer). In GIMP, duplicate the layer 3 times and set them to screen 50%, screen 50%, subtract 50%. This is the GIMP equivalent of photoshop's Exclusion (in other words, if using photoshop you don't have to duplicate, just set to exclusion 50%). This makes the image have a blue-ish effect (as you can see in the background) and gives Danny's skin both a yellow tint as well as a blue tint. You can choose a different color for this layer depending on the coloring you are going for. Flatten image.
In GIMP: Colors>Components>Channel Mixer
In Photoshop: Layer>New Adjustment Layer>Channel Mixer
With these settings:
Red: 150, -20, -10
Green: 5, 100, 0
Blue: 20, -5, 100
Preserve Luminosity Unchecked
Mess around with these settings until you get the desired coloring. This makes the icon much brighter and not as dull as it was from the previous step. It also makes the red in his shirt stand out more and gives his skin some pink as opposed to just blue and yellow as it was before. Depending on the natural skin color of the person in your icon, you may have to lower the first setting because you don't want their skin looking too red. Danny has pale skin, but in the icon I made of Tom with this coloring I had to lower the first one on Red (red: 150) because Tom's skin is already pink, and 150 just made it look really red. So, change the setting also based on the color of their skin. Later in this tutorial we will make the red shirt stand out, so do not worry about the fact that lowering the setting will make the shirt more dull as well.
Colors>Color Balance (or Layer>New Adjustment Layer>Color Balance)
Midtones: 15, 15, 20
Shadows: 3, -1, -7
Highlights: -1, 0, 10
Preserve Luminosity Checked because it keeps Danny's hair more natural looking and not reddish. Again, check preserve luminosity at your own discretion. In the icon with Tom I left it checked. It's just a matter of the hair color of your person really, or whether you want their hair to look more red.
This step is not necessary (depending on what you are going for), it just makes the icon whiter and takes some of the blue out of his skin (and out of the icon over all). Again, your settings will depend on your icon.
Now if we want Danny's red shirt to pop out...
New transparent layer. Get the color #ff0000 and with a paintbrush paint over his shirt (not the blue parts though). When you're done set this layer to Color 100%. With an eraser go over any parts you may have got on his skin or outside of the shirt. This simply makes his red shirt stand out more. Again, if you want the shirt more dull to kind of blend with the rest of the icon, skip this step.
You can stop there or add text.
Final Product:
Other example (with some tweaking and extra effects):
For this icon I messed with the channel mixer settings, because Tom's skin is naturally more red than Danny's and with the above settings it looked too red, so I toned down the red. Then when I finished I added a new transparent layer with a white fuzzy brush over Tom's chin area and set the layer to softlight. This brightened up the icon in the one area, giving it a subtly different lighting effect on the top and bottom. This is always a great step to use if you're looking to brighten up a single portion of your icon. Added some tiny text on the side. I left the step of painting over the shirt because in this icon it really made the shirt pop out.
to
using either The GIMP or Photoshop CS5.
Difficulty: Easy
Translatable: Yes, no selective coloring.
Other example:
First, take your base. I got mine from dont_be_so_base.
Add a new layer and fill it with 5c0000 (or if working in CS5--or any version of photoshop--just click new fill layer). In GIMP, duplicate the layer 3 times and set them to screen 50%, screen 50%, subtract 50%. This is the GIMP equivalent of photoshop's Exclusion (in other words, if using photoshop you don't have to duplicate, just set to exclusion 50%). This makes the image have a blue-ish effect (as you can see in the background) and gives Danny's skin both a yellow tint as well as a blue tint. You can choose a different color for this layer depending on the coloring you are going for. Flatten image.
In GIMP: Colors>Components>Channel Mixer
In Photoshop: Layer>New Adjustment Layer>Channel Mixer
With these settings:
Red: 150, -20, -10
Green: 5, 100, 0
Blue: 20, -5, 100
Preserve Luminosity Unchecked
Mess around with these settings until you get the desired coloring. This makes the icon much brighter and not as dull as it was from the previous step. It also makes the red in his shirt stand out more and gives his skin some pink as opposed to just blue and yellow as it was before. Depending on the natural skin color of the person in your icon, you may have to lower the first setting because you don't want their skin looking too red. Danny has pale skin, but in the icon I made of Tom with this coloring I had to lower the first one on Red (red: 150) because Tom's skin is already pink, and 150 just made it look really red. So, change the setting also based on the color of their skin. Later in this tutorial we will make the red shirt stand out, so do not worry about the fact that lowering the setting will make the shirt more dull as well.
Colors>Color Balance (or Layer>New Adjustment Layer>Color Balance)
Midtones: 15, 15, 20
Shadows: 3, -1, -7
Highlights: -1, 0, 10
Preserve Luminosity Checked because it keeps Danny's hair more natural looking and not reddish. Again, check preserve luminosity at your own discretion. In the icon with Tom I left it checked. It's just a matter of the hair color of your person really, or whether you want their hair to look more red.
This step is not necessary (depending on what you are going for), it just makes the icon whiter and takes some of the blue out of his skin (and out of the icon over all). Again, your settings will depend on your icon.
Now if we want Danny's red shirt to pop out...
New transparent layer. Get the color #ff0000 and with a paintbrush paint over his shirt (not the blue parts though). When you're done set this layer to Color 100%. With an eraser go over any parts you may have got on his skin or outside of the shirt. This simply makes his red shirt stand out more. Again, if you want the shirt more dull to kind of blend with the rest of the icon, skip this step.
You can stop there or add text.
Final Product:
Other example (with some tweaking and extra effects):
For this icon I messed with the channel mixer settings, because Tom's skin is naturally more red than Danny's and with the above settings it looked too red, so I toned down the red. Then when I finished I added a new transparent layer with a white fuzzy brush over Tom's chin area and set the layer to softlight. This brightened up the icon in the one area, giving it a subtly different lighting effect on the top and bottom. This is always a great step to use if you're looking to brighten up a single portion of your icon. Added some tiny text on the side. I left the step of painting over the shirt because in this icon it really made the shirt pop out.