plot point color change

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How do change the plot point color so that I can tell the difference between my three different equations? Here is what I have so far:

S = []
I = []
R = []

S.append(100000)
I.append(100)
R.append(0)

beta = 100
gamma = .4
lamda = 5e-006
mu = .001

i = 0
while(i<100):
    R.append(R[i] + (-mu * R[i] + gamma * I[i]))
    I.append(I[i] + (-mu * I[i] + lamda * S[i] * I[i] - gamma * I[i]))
    S.append(S[i] + (beta - mu * S[i] - lamda * S[i] * I[i]))

    i = i+1


N=range(1,100)

A = S
AN=zip(N,A)

B = I
BN=zip(N,B)

C = R
RN = zip(N,R)

plot(point(BN), legend_label = 'S(t)', color = 'green')