coloredCorners.py

x, y = 0, 0
w = h = 200
circles = 3
offset = 20
thickness = 26

color1 = (0, 1, 1)
color2 = (1, .5, 0)
color3 = (1, 0, 1)
color4 = (1, 1, 0)

colorMap = [
    (x, y, color1),
    (x + w, y, color2),
    (x, y + h, color3),
    (x + w, y + h, color4),
]

size(w, h)

for cx, cy, color in colorMap:
    fill(*color)
    oval(cx-thickness, cy-thickness, thickness*2, thickness*2)

blendMode("multiply")

path = BezierPath()
for i in range(circles):
    factor = i / (circles - 1)
    inset = offset + (w / 2-offset*2) * factor
    path.oval(x+inset, y+inset, w-inset*2, h-inset*2)
path = path.expandStroke(thickness)
clipPath(path)

for cx, cy, color in colorMap:
    radialGradient((cx, cy), (cx, cy), [color, (1, 1, 1, 0)], startRadius=0, endRadius=w)
    rect(x, y, w, h)