Blending 2 elements background colors using CSS

Question

I need to blend the background colors of 2 elements using CSS I have been fiddling around with the background-blend-mode:multiply but that works only when I have the 2 colors in the same element.

I need to achieve something like this -

---

I have been searching a lot but haven't been able to figure it out. Most helpful resource I found was New blending features in CSS which shows how to do it using Canvas. Is it possible to do the same thing using CSS?

EDIT

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The circles above were just an example to show what I needed. As I mentioned, I was looking for blending colors for 2 different elements. I have created a fiddle for my actual shapes that I need to blend. http://jsfiddle.net/fmgfsr4o/2/

Answer 1

You can combine CSS multiple background with radial-gradients to achieve this effect:

CSS

div {
  /* adjust the width of the container to adjust circle's
     overlap size and shape */
  width: 80px;
  height: 50px;
  /* for debug purpose only */
  border: solid blue 1px;

  background:
    /* draw the red circle */
    radial-gradient(red 0%, red 70%, transparent 70%, transparent 100%) 0 0,
    /* draw the green circle */
    radial-gradient(green 0%, green 70%, transparent 70%, transparent 100%) 0 0;
    /* the red on the left, the green on the right */
  background-position: top left, top right;

  /* you can make then bigger or smaller */
  /* but you have to change width size above too */
  background-size: 50px 50px;
  /* You want both circles to appears once only */
  background-repeat: no-repeat;

  /* you can try with other values too */
  /* https://developer.mozilla.org/en-US/docs/Web/CSS/background-blend-mode */
  background-blend-mode: multiply;
}

HTML

<div></div>

I have done a JSFiddle for you to try: http://jsfiddle.net/pomeh/07nLpwwj/

This is the result I get using Firefox 31:

Even if the browser support seems "correct" (see here http://caniuse.com/#feat=css-backgroundblendmode), please note that the background-blend-mode property has the Candidate Recommendation status for now, so be careful when using it (thanks to @Paulie_D for pointing that out).

Answer 2

Try this pure CSS3, although you will need to figure out how to position the circles.

html {
height: 100%;
background:
    repeating-radial-gradient(
        circle,
        transparent,
        transparent 3.5em,
        tomato 1em,
        tomato 4.5em
    ),
    repeating-radial-gradient(
        circle,
        transparent,
        transparent 3.5em,
        dodgerblue 3.5em,
        dodgerblue 4.5em
    );

background-blend-mode: multiply;
background-size: 10em 10em;
background-position:
    0 0,
    5em 5em,
    10em 5em;
}

JSFiddle