Is magnesium iodide a coloured salt?

Answer 1

It looks like Magnesium Iodide (and also its hexa- and octa-hydrates) is white or semi clear crystallic, solid salt.

However, though magnesium iodide is stable at even high heat under a hydrogen gas atmosphere, it decomposes in air at normal temperatures, turning brown from the release of elemental iodine. When heated in air, it decomposes completely to magnesium oxide and (purple vapor of) iodine. This can be checkes with wet starchy test paper becoming black.

Answer 2

No, magnesium iodide is a white salt. Magnesium compounds are typically colorless or white in appearance.