Using edges in a matplotlib table removes all others customizations

Question

I want a table without vertical lines. When I use edges='horizontal' all other customization disappears. Why is that?

df = pd.DataFrame({'Name':['Z', 'S', 'H'],
                  'Category':['A', 'A', 'A'],
                  'Number':[2,1,3],
                  'P':[0,0,0]})

col_col=[]
blue = '#00005A'
green = '#95C13E'

for i in range(len(df.columns)):
    col_col.append(blue)

fig, ax = plt.subplots()
plt.rcParams['font.family'] = 'Arial'

fig.patch.set_visible(False)
ax.axis('off')
ax.axis('tight')

colo = [["w",green,"w", green],["w",green,"w", green],["w",green,"w", green]] 

table=ax.table(cellText=df.values, 
               colLabels=df.columns, 
               loc='center', 
               colColours=col_col,
               cellColours=colo) 
#               edges='horizontal') # When I include this the colors disappear from the table