Antonyms of adj iridescent

2 senses of iridescent

Sense 1
changeable, chatoyant, iridescent, shot -- (varying in color when seen in different lights or from different angles; "changeable taffeta"; "chatoyant (or shot) silk"; "a dragonfly hovered, vibrating and iridescent")

INDIRECT (VIA colorful) -> colorless, colourless -- (weak in color; not colorful)

Sense 2
iridescent, nacreous, opalescent, opaline, pearlescent -- (having a play of lustrous rainbow colors; "an iridescent oil slick"; "nacreous (or pearlescent) clouds looking like mother-of-pearl"; "a milky opalescent (or opaline) luster")

INDIRECT (VIA bright) -> dull -- (emitting or reflecting very little light; "a dull glow"; "dull silver badly in need of a polish"; "a dull sky")

Similarity of adj iridescent

2 senses of iridescent

Sense 1
changeable, chatoyant, iridescent, shot -- (varying in color when seen in different lights or from different angles; "changeable taffeta"; "chatoyant (or shot) silk"; "a dragonfly hovered, vibrating and iridescent")
       => colorful (vs. colorless), colourful -- (having striking color; "colorful autumn leaves")

Sense 2
iridescent, nacreous, opalescent, opaline, pearlescent -- (having a play of lustrous rainbow colors; "an iridescent oil slick"; "nacreous (or pearlescent) clouds looking like mother-of-pearl"; "a milky opalescent (or opaline) luster")
       => bright (vs. dull) -- (emitting or reflecting light readily or in large amounts; "the sun was bright and hot"; "a bright sunlit room")