Tyrian purple the Iles Purpuraires at Mogador, in Morocco. The sea snail harvested at this western Moroccan dye production facility was "Hexaplex trunculus" (mentioned above) also known by the older name "Murex trunculus". This second species of dye murex is found today on the Mediterranean and Atlantic coasts of Europe and Africa (Spain and Portugal, Morocco, and the Canary Islands). The colour-fast (non-fading) dye was an item of luxury trade, prized by Romans, who used it to colour ceremonial robes. Used as a dye, the color shifts from blue (peak absorption at 590 nm, which is yellow-orange) to reddish-purple (peak absorption at
Trooping the Colour year emphasise the Queen's knowledge of the attributes of her guards, and single out "steadiness" as a highly prized quality for a guardsman. The accompanying marches always carry a flavour of the regiment whose colour is being trooped, lending the royal inspection a unique atmosphere. For example, if the Welsh Guards are trooping their colour, the music will include their traditional regimental march, "Men of Harlech". While the Queen passes the six companies of foot guards on her left, a slow march or air is played. Once the phaeton turns around the rear of No. 6 Guard, the music changes