cmap='colors' returns always blue color

edit

I provide the full code:

import ipywidgets as widgets
from ipywidgets import FloatSlider, Button
from IPython.display import display, clear_output
from sage.all import var, sinh, cosh, sin, sqrt, cos, tan, pi, implicit_plot3d, show
x,y,z = var('x y z') 
u, v, z, a = var('u v z a')
x, y, z = var('x y z')
coordinates = (a * sinh(v) / (cosh(v) - cos(u)), a * sin(u) / (cosh(v) - cos(u)), z)
show("Bispherical coordinates")
show(coordinates)

EtaSlider = FloatSlider(value=0.6, min=0.1, max=1.5, step=0.1, description='u:', orientation='horizontal', 
continuous_update=False)
ThetaSlider = FloatSlider(value=1.9, min=0.1, max=pi, step=0.1, description='v:', orientation='horizontal', continuous_update=False)
PsiSlider = FloatSlider(value=6.1, min=0, max=2*pi-0.1, step=0.1, description='z:', orientation='horizontal', continuous_update=False)
aSlider = FloatSlider(value=13.5, min=0.1, max=20, step=0.1, description='a:', orientation='horizontal', continuous_update=True)

display(EtaSlider)
display(ThetaSlider)
display(PsiSlider)
display(aSlider)

button = Button(description='Plot')
button.style.button_color = 'lightgreen'
display(button)

reset = Button(description='Reset values')
reset.style.button_color = 'lightgreen'
display(reset)

def update_plot(change=None):

    eta = float(EtaSlider.value)
    theta = float(ThetaSlider.value)
    psi = float(PsiSlider.value)
    a = float(aSlider.value)
    clear_output(wait=True)    

    f_1 = x**2 + y**2 + z**2 - a * (sqrt(((x**2 + y**2) / sinh(eta)**2) + z**2 / cosh(eta)**2))
    f_2 = x**2 + y**2 + z**2 - a * (sqrt((-(x**2 + y**2) / sin(theta)**2) + z**2 / cos(theta)**2))
    f_3 = x * tan(psi) / y    

    p = implicit_plot3d(f_1, (x, -30, 30), (y, -20, 20), (z, -20, 20), color='lightblue', opacity=0.9, mesh=False, 
frame=False, smooth=True)
    q = implicit_plot3d(f_2, (x, -20, 20), (y, -20, 20), (z, -20, 20), color='red', opacity=1, mesh=False, frame=False, 
smooth=True)
    r = implicit_plot3d(f_3, (x, -20, 20), (y, -20, 20), (z, -20, 20), color='lightgreen', opacity=1, mesh=False, frame=False, 
smooth=True)

    show("Inverse prolate spheroidal coordinates")
    show(coordinates)
    display(EtaSlider)
    display(ThetaSlider)
    display(PsiSlider)
    display(aSlider)
    display(button)
    display(reset)
    show("η:%s  θ:%s  ψ:%s a:%s" % (eta, theta, psi, a))
    show(p + q + r)



def reset_values(sender):

    EtaSlider.value = 5.6
    ThetaSlider.value = 1.9
    PsiSlider.value = 6.1
    aSlider.value = 13.5


EtaSlider.observe(update_plot, names='value')
ThetaSlider.observe(update_plot, names='value')
PsiSlider.observe(update_plot, names='value')
aSlider.observe(update_plot, names='value')
button.on_click(update_plot)
reset.on_click(reset_values)

update_plot()

Now, exchange now in the implicit implicit_plot3d : color='...' by 'cmap='Reds' , cmap='Blues', cmap='Greens' in the three functions. All colors then will be blue