Gray

Gray or grey is the color of black and white mixed together. 
Gray is the color of an elephant, cement, pencil writing, and rainy clouds. Gray often looks like someone made black lighter, but not so light that it is white. 
Grey color represents neutrality and balance. 
In the United Kingdom, Australia, South Africa, India, Ireland, and New Zealand, as well as a few other countries, this word is spelled grey. In the United States and Canada, it is spelled gray.
The first recorded use of "gray" as a color name in English was in 700. 
Shades of grey colour comparison chart.
The chart below shows those shades of grey that are major web colours.