A security element including substrate on which is disposed: in first area, a first optically variable device including a diffractive or reflective relief structure and reflection enhancing material following contours of relief structure; and, in second area, a second optically variable device including an iridescent amplitude interference material. First optically variable device is constituted by a plurality of sub-areas arranged in cyclically repeating sequence along predetermined direction of the security element, the plurality of sub-areas collectively forming first area. Relief parameters of diffractive or reflective relief structure vary from one sub-area to next within each repeat cycle whereby, at any viewing angle, each sub-area within any repeat cycle exhibits different diffractive color or reflected intensity from those of other sub-areas within same repeat cycle, so, when device is tilted, different diffractive colors or reflected intensities appear to move from one sub-area to next within each repeat cycle along predetermined direction.