Tryit Editor v1.8

Source Code:
<!DOCTYPE html>
<html>
<body>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
  <defs>
    <linearGradient id="MyGrad" gradientUnits="userSpaceOnUse" x1="50" y1="0" x2="600" y2="0">
      <stop offset="0" stop-color="#ff0000" />
      <stop offset=".33" stop-color="#00ff00" />
      <stop offset=".67" stop-color="#0000ff" />
      <stop offset="1" stop-color="#000000" />
    </linearGradient>
    <filter id="Identity">
      <feComponentTransfer>
        <feFuncR type="identity" />
	    <feFuncG type="identity" />
        <feFuncB type="identity" />
	    <feFuncA type="identity" />
      </feComponentTransfer>
    </filter>
    <filter id="Table">
	  <feComponentTransfer>
        <feFuncR type="table" tableValues="0 0 1 1" />
	    <feFuncG type="table" tableValues="1 1 0 0" />
        <feFuncB type="table" tableValues="0 1 1 0" />
      </feComponentTransfer>
    </filter>
    <filter id="Linear">
      <feComponentTransfer>
        <feFuncR type="linear" slope=".5" intercept=".25" />
	    <feFuncG type="linear" slope=".5" intercept="0" />
        <feFuncB type="linear" slope=".5" intercept=".5" />
      </feComponentTransfer>
    </filter>
    <filter id="Gamma">
      <feComponentTransfer>
        <feFuncR type="gamma" amplitude="2" exponent="5" offset="0" />
	    <feFuncG type="gamma" amplitude="2" exponent="3" offset="0" />
        <feFuncB type="gamma" amplitude="2" exponent="1" offset="0" />
      </feComponentTransfer>
    </filter>
  </defs>
  <g font-size="50" font-weight="bold" fill="url(#MyGrad)">
    <text x="50" y="60" filter="url(#Identity)">Identity</text>
    <text x="50" y="120" filter="url(#Table)">TableLookup</text>
    <text x="50" y="180" filter="url(#Linear)">LinearFunc</text>
    <text x="50" y="240" filter="url(#Gamma)">GammaFunc</text>
  </g>
</svg>

</body>
</html>
Result:
W3Schools.com - Try it yourself