Plot.plot({
width: 300,
height: 100,
margin: 2,
marks: [
Plot.frame({ anchor: "left", stroke: "red", strokeWidth: 4 }),
Plot.frame({ anchor: "right", stroke: "green", strokeWidth: 4 }),
Plot.frame({ anchor: "top", stroke: "blue", strokeWidth: 4 }),
Plot.frame({ anchor: "bottom", stroke: "black", strokeWidth: 4 })
]
})