title: Getting black plots with plt.imshow after multiplying RGB image array by a scalar
body: <p>So I am a bit confused as to why this is happening.</p>
  
  <p>I have a binary image:
  <a href="https://i.stack.imgur.com/XNgTL.png" rel="noreferrer"><img src="https://i.stack.imgur.com/XNgTL.png" alt="enter image description here"></a></p>
  
  <p>Now I want to convert this binary image into RGB space, so therefore I use the <code>dstack</code> function to concatenate the 3rd axis</p>
  
  <p><a href="https://i.stack.imgur.com/lphWT.png" rel="noreferrer"><img src="https://i.stack.imgur.com/lphWT.png" alt="enter image description here"></a></p>
  
  <p>Everything works fine so far, but now I have to multiply the <code>out_image</code> array by <code>255</code> to reflect white in RGB space, and this is where the problem occurs everything turns black<a href="https://i.stack.imgur.com/0gEC4.png" rel="noreferrer"><img src="https://i.stack.imgur.com/0gEC4.png" alt="enter image description here"></a></p>
  
  <p>But if I plot another random image, everything is fine so what is happening here, I've also played around with the <code>cmap</code> but regardless of what kind of <code>cmap</code> I use it always turns out to be black when multiplied by <code>255</code></p>
  
  <p>Any ideas?</p>