title: fix position colorbar for multiple plot plotly
body: <pre><code>x1 = c(1:10)
  y1 = c(1:10)
  z1 = matrix(runif(100,0,25),ncol = 10)
  z1_col = matrix(runif(100,0,25),ncol = 10)
  
  x2 = c(2:11)
  y2 = c(2:11)
  z2 = matrix(runif(100,0,100),ncol = 10)
  z2_col = matrix(runif(100,0,25),ncol = 10)
  
  x3 = c(3:12)
  y3 = c(3:12)
  z3 = matrix(runif(100,0,10),ncol = 10)
  z3_col = matrix(runif(100,0,25),ncol = 10)
  
  x4 = c(3:12)
  y4 = c(3:12)
  z4 = matrix(runif(100,0,5),ncol = 10)
  z4_col = matrix(runif(100,0,25),ncol = 10)
  </code></pre>
  
  <p>I am trying to fix the position of the colorbar in plotly. I have already try to fix it by putting in the x and y axis of the color bar for each plot.</p>
  
  <pre><code>plot_ly(type = "surface", colors = c("blue","green","yellow","orange","red")) %&gt;%
    add_trace(x = ~ x1, y = ~ y1, z = ~ z1, surfacecolor = ~ z1_col,
              colorbar = list(title = "Concentration", x = 1, y = 0.5)) %&gt;%
    add_trace(x = ~ x2, y = ~ y2, z = ~ z2, surfacecolor = ~ z2_col,visible = F,
              colorbar = list(title = "Concentration", x = 1, y = 0.5)) %&gt;%
    add_trace(x = ~ x3, y = ~ y3, z = ~ z3, surfacecolor = ~ z3_col,visible = F,
              colorbar = list(title = "Concentration", x = 1, y = 0.5)) %&gt;%
    add_trace(x = ~ x4, y = ~ y4, z = ~ z4, surfacecolor = ~ z4_col,visible = F,
              colorbar = list(title = "Concentration", x = 1, y = 0.5)) %&gt;%
    layout(updatemenus = list(
      list(
        y = 0.8,
        # FOR line, point, to show A, list(T,F,F)
        # but for 3D, list (F,T,F)
        buttons = list(
          list(method = "restyle",
               args = list("visible",list(F,T,F,F)),
               label = "A"),
          list(method = "restyle",
               args = list("visible",list(F,F,T,F)),
               label = "B"),
          list(method = "restyle",
               args = list("visible",list(F,F,F,T)),
               label = "C"),
          list(method = "restyle",
               args = list("visible",list(T,F,F,F)),
               label = "D")
        )
      )
    ))
  </code></pre>
  
  <p>However, whenever I change to a new plot, the position of the color bar changes (shifting downward). 
  <a href="https://i.stack.imgur.com/ALY61.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ALY61.png" alt="enter image description here"></a>
  <a href="https://i.stack.imgur.com/tCSrr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tCSrr.png" alt="enter image description here"></a>
  Is there any way to fix the position of the color bar for all the plot ?</p>