Incongruous
/ɪnˈkɑːŋɡruəs/ adjective mediumOut of place; not fitting with its surroundings or with what would normally be expected.
The bright orange sneakers looked incongruous with his formal black suit.
Memory Trick
'In-' (not) plus 'congruous' (matching, as in geometry's 'congruent' shapes) — incongruous things simply don't line up.