title: Apply opacity to theme color keeeping the tie to the original color
body: <p>In Google Slide, I would like to use a theme color and apply opacity to it.</p>
  <p>I know I can do this by adding a new color and setting the transparency, the problem is that when I change the theme color, the new transparent color will not change.</p>
  <p>Up until today, I thought this was just a missing feature in Google Slides, but a template I bought from a marketplace, has this exact feature, i.e. there is a shape which has a theme color and is also transparent, the problem is that I cannot change the transparency without incurring in the above mentioned problem.</p>
  <p>My question is, is there a way to change the transparency and also keep the color tied to the theme color?</p>
  <p>As an example, what I want to achieve is: create shape_1 and give it theme_color_1 (let's say it is #0029FFFF). Set transparency of shape_1 to 50% (so the color is #0029FF80). Change theme_color_1 (say to #44FF32FF). I want shape_1 to have new color #44FF3280.</p>