Low-light vision + darkvision = ?

[Tarpeius]

The Summoner feat Expanded Senses makes a point of granting eidolons both low-light vision and darkvision. How is this different than just granting them darkvision?

[Squiggit]

Darkvision is black and white only. A creature with both can see perfectly and in color in dim light and in black and white in darkness.

A creature with only darkness can't see colors in dim light.

[Tarpeius]

Oh, okay, thanks. Where's that found?

[Tarpeius]

Actually, I'm seeing it clearly in the second printing. Thanks!