I got bored so I made two very simple tutorials. I'm using Photoshop 7 but should work in other versions as well.
to
1. Resize and crop your picture to 100x100.
2. Layers » New Adjustment Layer » Hue/Saturation. Set the saturation to +45.
3. Layers » New Adjustment Layer » Selective Color.
Red
Cyan: -100
Magenta: 0
Yellow: 0
Yellow
Cyan: -100
Magenta: 0
Yellow: 0
Cyan
Cyan: -100
Magenta: -100
Yellow: -100
Blue
Cyan: -100
Magenta: -100
Yellow: -100
4. Flatten. Filter » Sharpen » Sharpen. Fade sharpen: 20%
It's pretty damn close to the original, don't you think?
to
1. Open up your base, resize, and crop to 100x100.
2. Layers » New Adjustment Layer » Hue/Saturation. Set the saturation to +60.
3. Layers » New Adjustment Layer » Selective Color.
Red
Cyan: -100
Magenta: 0
Yellow: 0
Yellow
Cyan: +100
Magenta: 0
Yellow: 0
Green
Cyan:
Magenta:
Yellow:
Cyan
Cyan: -100
Magenta: -100
Yellow: +100
Blue
Cyan: +100
Magenta: -100
Yellow: -100
Magenta
Cyan: -100
Magenta: +100
Yellow: 0
White
Cyan: +100
Magenta: 0
Yellow: -100
4. Flatten. Filter » Sharpen » Sharpen. Fade sharpen: 50%
Again, it's not exactly the same but it's close enough :)
Remember, the outcome depends on the original picture. It will not always work. Have fun with this!