R.<x,y> = PolynomialRing(QQ,2)
var('z')
f1 = 432*x^5+144*x^4*y-504*x^3*y^2-168*x^2*y^3+99*x*y^4+33*y^5+36*x^4*z-13*x^2*y^2*z+y^4*z-540*x^3*z^2-180*x^2*y*z^2+216*x*y^2*z^2+72*y^3*z^2-45*x^2*z^3+108*x*z^4+36*y*z^4+9*z^5
f = f1.subs(x=1,y=x,z=y)
ff(x,y) = f
mylinewidth = 4.5
bb1 = (-4,6)
bb2 = (-3,3)

G = Graphics()
G += region_plot([ff>=0],(x,-1.2,1.2),(y,-1.2,1.2), ticks=[[],[]], axes=false, gridlines=False,incol='lightgreen')
G += implicit_plot(ff, bb1, bb2, linewidth=mylinewidth, ticks=[[],[]], axes=false, gridlines=False, color="blue")
G.axes(False)
G.axes_label_color('white')

G.show(ticks=[[],[]], axes=False, gridlines=False) # dpi = 100