monochrome
/ˌmɑnəˈkrōm, ˌmoʊn-/Definitions
1. adjective
having or producing only one color or shades of a single color
“The artist’s monochrome painting was a bold statement about simplicity.”
2. noun
a work of art that uses only one color or shades of a single color
“The museum exhibit featured a collection of monochrome paintings from the 20th century.”