Answer: darkener

AnswerCrossword Clue
DARKENERBrown paint, e.g.
darkenermake dark
darkenerone that darkens (to make dark (having little light))
darkenerbecome gloomy his mood darkened
darkenermake of darker color
darkenercast a gloom over
darkenerto grow dark become obscured the skies were darkening
darkenermake less clear obscure the financial crisis darkened the future of the company