One of our favorites, Andy Clarke, on the one thing keeping the CSS contrast-color() function from true glory:
…For my website design, I chose a dark blue background colour (
#212E45) and light text (#d3d5da). This
repeating-linear-gradient() function creates a repeating gradient that places colors along a straight line and smoothly transitions between them. We define a section of the gradient, which then gets repeated until it fills the available space. 
light-dark() function is currently designed to support just two color schemes. Should it support others? Sunkanmi Fafowora says yes and no. conic-gradient() function creates a color gradient that places the colors around a circle, making them smoothly transition across its circumference in a cone-like shape. 
radial-gradient() functions creates a circular or elliptical color gradient starting from a center point and spreading outward. repeating-radial-gradient() function creates a circular or elliptical color gradient. The gradient is then repeated infinitely.