Question

I want to write a simple rectangle with a red shadow in SVG.
I have a simple filter:

<svg xmlns="http://www.w3.org/2000/svg" version="1.1" width="1012" height="400">
  <title>svg arrow with dropshadow</title>
  <desc>An svg example of an arrow shape with a dropshadow filter applied. The dropshadow filter effect uses feGaussianBlur, feOffset and feMerge.</desc>
  <defs>
    <filter id="dropshadow" filterUnits="userSpaceOnUse" color-interpolation-filters="sRGB">
     <feComponentTransfer in="SourceAlpha">
         <feFuncR type="discrete" tableValues="1"/>
         <feFuncG type="discrete" tableValues="0"/>
         <feFuncB type="discrete" tableValues="0"/>
     </feComponentTransfer>
     <feGaussianBlur stdDeviation="2"/>
     <feOffset dx="0" dy="0" result="shadow"/>
     <feComposite in="SourceGraphic" in2="shadow" operator="over"/>
   </filter>
  </defs>
  <rect rx="2" ry="2" fill="rgb(255,255,255)" x="5.25" y="5.25" width="141" height="50" fill-opacity="0.85" filter="url(#dropshadow)">
</svg>

Why in this example shadow color is not red? Where is my bad?

Answer 1

1. You have provided invalid SVG – you need to close your <rect> element.

2. Your example (fixed) shows a red shadow for me in Chrome. Here’s what this URL looks like for me with Chrome v15:

   

What OS/browser/version are you seeing different results with?

Edit: In Firefox v7 I see all greyscale, and in Safari v5 I don’t see the shadow effect at all. Your answer, most likely then, is simply that you’re testing in a browser/version with incomplete support of the SVG filter specification.