Mox Amber

Mox Amber’s ability adds one mana of the color of your choice from among the colors of legendary creatures and planeswalkers you control. It doesn’t add one mana of each of those colors.

If you control no legendary creatures or planeswalkers, you can activate Mox Amber’s ability, but you won’t add any mana.

If your legendary creatures and planeswalkers are all colorless, you can activate Mox Amber’s ability, but you won’t add any mana. Colorless is not a color.