Minimal example for one stop gradients exported from Inkscape

onestopgradient.svg

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!-- Created with Inkscape (http://www.inkscape.org/) -->

<svg
   xmlns:dc="http://purl.org/dc/elements/1.1/"
   xmlns:osb="http://www.openswatchbook.org/uri/2009/osb"
   xmlns:cc="http://creativecommons.org/ns#"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:xlink="http://www.w3.org/1999/xlink"
   version="1.1"
   width="744.09448"
   height="1052.3622"
   id="svg2">
  <defs
     id="defs4">
    <linearGradient
       osb:paint="solid"
       id="linearGradient3761">
      <stop
         style="stop-color:#a8c4cc;stop-opacity:1;"
         offset="0"
         id="stop3763" />
    </linearGradient>
    <linearGradient
       x1="353.83112"
       y1="396.85037"
       x2="496.56262"
       y2="396.85037"
       id="linearGradient3765"
       xlink:href="#linearGradient3761"
       gradientUnits="userSpaceOnUse" />
  </defs>
  <g
     transform="translate(0,-2)"
     id="layer1">
    <rect
       width="150"
       height="150"
       x="350"
       y="350"
       transform="translate(0,2)"
       id="rect_one-stop-gradient"
       style="fill:url(#linearGradient3765);fill-opacity:1;stroke:#ffffff;stroke-width:0.99921262;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-opacity:1;stroke-dasharray:none;stroke-dashoffset:0" />
    <rect
       width="150"
       height="150"
       x="50"
       y="350"
       transform="translate(0,2)"
       id="rect_simple-fill"
       style="fill:#a8c4cc;fill-opacity:1;stroke:#ffffff;stroke-width:0.99921262;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-opacity:1;stroke-dasharray:none;stroke-dashoffset:0" />
  </g>
</svg>