Random Colour Picker : I know this question has been asked before but I can never seem to find it in the right context. For my website, I want, upon loading the page, a random colour to be generated (1 of the rainbow). Then whenever I hover over a div (it is one that is repeated), that div/s will become the specified colour.

    .shape:hover {
		    background-color: green;
			transition-duration: 0.1s;
		}

That's the CSS. The current background colour is green but that's the property I want to be randomly selected upon the page loading. Thanks.