Color
Hex color in number format:
do 0x0000ff
or generate from HSL color:
quatrefoil.core/hslx 200 80 80
HSLuv color based on hsluv:
quatrefoil.core/hsluvx 300 70 90
HCL color is also supported based on d3-color:
quatrefoil.core/hclx 300 70 90