Improvements to random palette picker

[webinista]

Try to avoid colors that fall within the original's degree range. For example, if original color works out to hsl(110, 98%, 50%), a yellow-green, should not pick another value between 90 and 120, which is the range for yellow-greens.

https://drafts.csswg.org/css-color-4/#hsl-examples

Randomizing saturation and lightness values will create more variation in random palettes. But may add clashing colors to the mix.

[webinista]

A neat maths trick allows us to generate random appearing colours with fewer collisions.

Multiples of the golden angle (~137.6 degrees) has a nice property of landing on visually distinct points on the colour wheel where colours seldom colide.

Example from the article:

function (el, i) {
  el.style.background = 'hsl(' + 137.50 * i + 'deg, 80%, 80%)';
}

https://medium.com/samsung-internet-dev/human-friendly-colours-using-hsl-4944bcdb6e27