I love seeing tutorials so I thought I'd try my hand at sharing one. This is a coloring tutorial designed to make somewhat desaturated, cool-toned images a bit livelier, playing up reds and blues.
Note: I don't particularly like results I've gotten when using this coloring on warm-toned images (especially ones with lots of yellow), so be aware that the initial image you choose will definitely effect your end product.
This tutorial uses Photoshop CS5 and is not translatable to other programs.
Step 1: Start with your 100x100 base, prepared however you prefer. It should be fairly bright but don't wash out details.
Step 2: Layer > New Adjustment Layer > Vibrance
Step 3: Layer > New Adjustment Layer > Selective Color
Reds: -50 / -20 / +30 / +20
Yellows: -30 / -30 / +100 / 0
Cyans: +100 / +30 / +30 / +100
Blues: +100 / +20 / +20 / +100
Magentas: -20 / +100 / -20 / 0
Whites: -80 / -80 / -80 / -80
Neutrals: +20 / +20 / 0 / -20
Step 4: Layer > New Adjustment Layer > Selective Color
Reds: -30 / -10 / +20 / 0
Greens: +100 / -100 / +94 / 0
Step 5: Layer > New Fill Layer > Solid Color
Fill with 08192a and set to Exclusion, 100%.
Step 6: Layer > New Fill Layer > Solid Color
Fill with edb966 and set to Soft Light, 30%.
Step 7: Layer > New Fill Layer > Solid Color
Fill with 010a0e and set to Exclusion, 100%.
Step 8: Duplicate the background (bottom layer) and drag it to the top. Select this layer. Image > Adjustments > Hue/Saturation
Step 9: With your duplicated background layer selected, Filter > Blur > Gaussian Blur
Set this layer to Saturation, 50%.
Step 10: Duplicate the original background and drag it to the top. Layer > New Fill Layer > Solid Color.
Fill with 283069 and set to Exclusion, 100%.
Step 11: Select the two topmost layers (probably "Color Fill 4" and "Background copy 2"). Layer > Merge Layers. Image > Adjustments > Desaturate
Step 12: Set the desaturated layer to Luminosity, 30%.
Step 13: Duplicate the background and drag it to the top. Set this layer to Soft Light, 50%.
Step 14: Layer > New Fill Layer > Solid Color
Fill with f3538f and set to Saturation, 10%.
And there's the finished product.
No credit is necessary but if you use this I'd love to see what you make.