Fix SVG Serializer Color Issue

[kayuri]

Fill/stroke fill color is not serialized correctly.

Example:

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" id="svg-root" width="100%" height="100%" viewBox="0 0 480 360">
    <g font-family="Andalus,Diwani Letter,serif">
      <path d="M10,120 L470,120" stroke="#BBB"/>
      <path d="M10,240 L470,240" stroke="#BBB"/>
      <text text-anchor="middle" x="240" y="120" font-size="140" xml:lang="ar" fill="#700">&#1570;&#1604;&#1575;&#1578;</text>
      <text text-anchor="middle" x="240" y="240" font-size="140" xml:lang="ar" fill="#700">&#1579;&#1604;&#1575;&#1579;&#1577;</text>
</svg>

Parsed and serialized as:

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1">
  <g>
        <path d="M 10 120L 470 120" fill="black" stroke="#000BBB" stroke-width="1.0"/>
        <path d="M 10 240L 470 240" fill="black" stroke="#000BBB" stroke-width="1.0"/>
        <text y="120" x="240" font-family="Andalus,Diwani Letter,serif" font-size="140" font-weight="normal" text-anchor="middle" fill="#000700">&#x622;&#x644;&#x627;&#x62A;</text>
        <text y="240" x="240" font-family="Andalus,Diwani Letter,serif" font-size="140" font-weight="normal" text-anchor="middle" fill="#000700">&#x62B;&#x644;&#x627;&#x62B;&#x629;</text>
      </g>
</svg>

[f3dm76]

Now it is serialized to

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1"  >
    <g>
        <g>
        <path  d="M 10 120L 470 120"  fill="black" stroke="#BBBBBB" stroke-width="1.0"/>
        <path  d="M 10 240L 470 240"  fill="black" stroke="#BBBBBB" stroke-width="1.0"/>
        <text    font-family="Andalus,Diwani Letter,serif" font-size="140"  font-weight="normal"  text-anchor="middle"  fill="#770000" transform="translate(240,120)" >آلات</text>
        <text    font-family="Andalus,Diwani Letter,serif" font-size="140"  font-weight="normal"  text-anchor="middle"  fill="#770000" transform="translate(240,240)" >ثلاثة</text>
    </g>
</g>
</svg>

Colors are fine. Vertical text alignment is not, but that's another issue #391