Geometry
The figure is one parametric curve drawn for t in [−c, c], then rotated four times by 90° to form a symmetric rosette.
x(t) = a · sin³(−b·t) · 3cos(cos(d·t))
y(t) = a · sin(sin(−b·t)) · cos³(d·t)
Colour encodes distance from the origin: warm and bright at the centre, cooling and dimming gradually toward the rim.