Yes, the bottom is really that bright. I've put on a turpentine wash consisting of quinacridone coral and cadmium orange. Rather than have a fairly neutral base to the tundra, this will be intense. Most of the color will be covered but the little that peaks through will mimic the bright reds and oranges of the fall tundra.
Until I get some of the tundra painted, it is a rather distracting color throwing off the carefully orchestrated palette. But I believe the end result will be worth the visual discordance.