I am trying to normalize a colorbar (-350,350) and than plot in an subplot of the figure.

Now I am doing this:

cmap= cmocean.cm.balance
ax3 = fig.add_subplot(spec[2])

cmap =cmocean.cm.balance
norm1 = matplotlib.colors.Normalize(vmin=-350,vmax=350)

cb = mpl.colorbar.ColorbarBase(ax3,cmap=cmap,norm=norm1,ticks=np.arange(-150,350,50),extend='both',label=r'[Sv]',orientation='vertical')

and I get this:

.

but I want to cut the color bar and only get -150:350