title: Imitate Photoshop blend effects like multiply, overlay etc
body: <p>I'm making a website with a full page background image. I want to create a background image for a side column that acts like a Photoshop layer with multiply as blend mode. It's just a blue colored surface with the 'behaviour' of a Photoshop multiply layer.</p>
  
  <p>It's not possible to merge the overlay and the image since the background can change when the website is opened in another screen ratio/size.</p>
  
  <p><img src="https://i.stack.imgur.com/uVsxB.jpg" alt="enter image description here"></p>
  
  <p>There are a lot of solutions on SO, but they only work with multiplying 2 images with a fixed position, not a colored surface with variable position/background. </p>
  
  <p>Are there tricks to achieve this?</p>