changeable

capable of or tending to change in form or quality or nature

• “a mutable substance”
• “the mutable ways of fortune”
• “mutable weather patterns”
• “a mutable foreign policy”

such that alteration is possible; having a marked tendency to change

• “changeable behavior”
• “changeable moods”
• “changeable prices”

subject to change

• “a changeable climate”
• “the weather is uncertain”
• “unsettled weather with rain and hail and sunshine coming one right after the other”

varying in color when seen in different lights or from different angles

• “changeable taffeta”
• “chatoyant (or shot) silk”
• “a dragonfly hovered, vibrating and iridescent”