Filbik colour coder
From Tardis Wiki, the free Doctor Who reference
A Filbik colour coder was a device used by the Filbik to catalogue samples of life from alien planets and transport them safely to nearby storage ships. It had the appearance of a gold-coloured rock. The colour coder would change the colour of any sample it was used on, and could do so in any colour of the rainbow. It also released a low-level sedative, so that living samples would be put to sleep in order to transport them more safely. (PROSE: The End of the Rainbow)