问如何设置包含热图的两个水平子图，使它们不共享一个色标？

EN

import plotly.plotly as py
import plotly.graph_objs as go
import plotly
plotly.offline.init_notebook_mode()

mm = go.Heatmap(
        z=[[1, 20, 30],
           [20, 1, 60],
           [30, 60, 1]],
        colorbar = dict(x=0.45), 
    colorscale='Viridis'
    )
sm = go.Heatmap(
        z=[[1, 2, 3],
           [2, 1, 6],
           [3, 6, 1]]
    )
fig = plotly.tools.make_subplots(rows=1, cols=2)
fig.append_trace(mm, 1, 1)
fig.append_trace(sm, 1, 2)

plotly.offline.iplot(fig)

fig = make_subplots(rows=1, cols=6,
                    subplot_titles=("Web", "Magasin", "Email"),
                    specs=[[{}, None, {}, None, {}, None]],
                    shared_yaxes=True)

fig.add_trace(go.Heatmap(
    z=df_web.values,
    x=df_web.columns.tolist(),
    y=df_web.index.tolist(),
    colorscale='RdBu',
    reversescale=True,
    colorbar = dict(x=0.27, title='Nb moyen', thickness=15)), row=1, col=1
)

fig.add_trace(go.Heatmap(
    z=df_mag.values,
    x=df_mag.columns.tolist(),
    y=df_mag.index.tolist(),
    colorscale='RdBu',
    reversescale=True,
    colorbar = dict(x=0.62, title='Nb moyen', thickness=15)), row=1, col=3
)

fig.add_trace(go.Heatmap(
    z=df_email.values,
    x=df_email.columns.tolist(),
    y=df_email.index.tolist(),
    colorscale='RdBu',
    reversescale=True,
    colorbar = dict(x=0.97, title='Nb moyen', thickness=15)), row=1, col=5
)

fig.update_layout(title_text='Répartition par jour et heure', title_x=0.5,
                height=250, margin=dict(l=0,r=0,b=50,t=25),
                xaxis=dict(
        domain=[0, 0.27]
    ),
    xaxis2=dict(
        domain=[0.35, 0.62]
    ),
    xaxis3=dict(
        domain=[0.7, 0.97]
    ))