It's made in the shade.

Consumers sometimes report this as gray or even greenish skin. Whatever, the photo in the upper right has a case of it.

Most people — even good photographers with calibrated monitors — don't notice it online. But in print, watch out...

Why is that? Because your eyes remove color casts. On a small screen, there's usually no correctly-balanced shot to compare to. But in print, you have your hands, the room, other people... Your eyes are only good at comparisons.

In fact, to your eyes, the little boy's face may look too red in the lower right photo. But the Info window, below it, clearly shows it's actually still a little too blue (how we know that). But you're comparing it to the one above, your only reference point, and by comparison it looks red.

What causes this blue?

Shade. Direct sun doesn't land there, only scattered light. Blue scatters much more than yellow, so shade has more blue relative to yellow than direct sun does.

But...why doesn't the camera adjust? Because all digital cameras still have terrible auto white balance.

But...I manually set my camera to the shade white balance setting!

Unfortunately, the camera manufacturer is guessing about your shade because the deeper the shade, the bluer it is.

If you shoot on the edge of shade with faint shafts of sun peeking through the leaves of a tree, the shade setting will take care of you. But if you move deep into the trees or a building's shadow, the shade setting is not strong enough medicine to prevent the blues.

Yuck. Make it go away.

The best way is to manually set your white balance with an expodisc or white card.

Choosing autocorrect in the shopping cart will help, but won't make them perfect. Better is to follow the guidelines in the pleasing skin tone help section.