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Improve time to plot a set of points

I try to draw clouds of coloured dots. The coordinates of the points are given by a formula. Let's say they're randomly distributed in [0,1]: that doesn't really matter here and isn't the problem.

For the plot, I use the following code. It's remarkably slow (in the sense that I didn't expect it to take so long).

The options don't seem to be the cause of the slowdown (*), but they do limit my use of list_plot, which seems to be much more efficient.

For example, with the following code:

the total CPU time for Trace() is 1min
the total CPU time for Trace2() is 121ms

I'm looking for ideas on how to improve the time it takes to draw my colored dots (I'd probably have to find a suitable python library, but I'm far from an expert...).

N = 10^4
R = range(N)
P=[(randrange(N)/N*1.0,randrange(N)/N*1.0) for k in R]
#..................
def mycolorscale(k):
    return Color(1 - k/N, 0, 0)
#..................
def Trace():
    g=Graphics()
    k=0
    for p in P:
        g+=point(p,rgbcolor=mycolorscale(k),size=1)
        k+=1
    g.show()
#..................
def Trace2():
    list_plot(P,plotjoined=False,size=1).show()

(*) Replacing

g+=point(p,rgbcolor=mycolorscale(k),size=1)

g+=point(p)

in the Trace code changes essentially nothing to the duration.