Colors

Think of onyx as a grey or dark cream.

The attached image, showing "Cultured Onyx Colors," and the first sentence, suggesting that we "[t]hink of onyx as a grey or dark cream," have been copied from the Internet.

Poul Anderson, describing a natural scene, appeals to four senses. East of Windhome on the planet Aeneas, there is low country, then the Hesperian Hills. In summer, leaves are shades of green on two kinds of imported Terrestrial trees, rasmin is purple and the local equivalent of grass, fire trava, is "...onyx tinged with red and yellow..." -Poul Anderson, Captain Flandry: Defender Of The Terran Empire (New York, 2010), p. 76.

There is a cold draught and the flint and spark daytime odor of the fire trava has almost gone. Rustling sounds "...like whispers in an unknown tongue..." (ibid.) pass through a large native tree. One of the moons climbs visibly, like Edgar Rice Burroughs' Barsoomian moons.

Thus, Ivar Frederiksen, waiting to lead an ambush, experiences colors, cold, a fading odor and mysterious sounds. It is worthwhile to pause on this scene, and many like it, rather than to race ahead to read about the ambush.