Walnut
When we think of walnut furniture, typically we would picture something that is nearly uniformly of brown color. The truth is that walnut is more varied in color and grain than most other woods, but it is usually supplied steamed, to darken the sapwood.
The heartwood (found in the center of a tree) of walnut is usually a dark chocolate color, or a lighter brown color with darker streaks. I have seen some with purple-ish and reddish streaks.
The sapwood (found closer to the bark) can vary from peanut butter color to gold to bright orange to white. I’ve seen some slabs with blue and purple streaks in it as well.