Dusty riverbed grey, where the valley's lowest point meets the sky.
Valley Floor is a cool grey.
It can be described as cool, muted, greyish and dusty.
Set in black, because black reads best on it.
A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a very long period. Some valleys are formed through erosion by glacial ice. These glaciers may remain present in valleys in high mountains or polar areas.
Read on WikipediaA floor is the bottom surface of typically an enclosed space such as a room or vehicle. Floors vary from simple dirt in a cave to many layered surfaces made with modern technology. Floors may be stone, wood, bamboo, metal, or any other material that can support the expected load.
Read on WikipediaNoun