Configure MacOS Desktop background color with defaults command

I use a number of defaults write commands for configuring Mac system settings. I have yet to find one for setting a solid background color for the Desktop. I've tried a few variations of com.apple.dock and com.apple.desktop but am unsure of the setting key. I would like to be able to set the background color with a hex color value. Something like defaults write com.apple.desktop backgroundColor '#a6889b'. Any ideas?