I draw 2 rectangles filled with 2 swatchs: color1, color2,.
And I draw a circle with a gradiant: grad1
Is it possible to definite the gradiant from color1 & colors2  in order when I modify one swatch, it modifies the stop of my gradient ?
My svg to do it:
 

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

<svg
   width="210mm"
   height="140mm"
   viewBox="0 0 210 140"
   version="1.1"
   id="svg24396"
   xmlns:xlink="http://www.w3.org/1999/xlink"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:svg="http://www.w3.org/2000/svg">
  <defs
     id="defs24393">
    <linearGradient
       id="color2">
      <stop
         style="stop-color:#9acd32;stop-opacity:1;"
         offset="0"
         id="stop36285" />
    </linearGradient>
    <linearGradient
       id="color1">
      <stop
         style="stop-color:#ff1493;stop-opacity:1;"
         offset="0"
         id="stop36279" />
    </linearGradient>
    <linearGradient
       id="grad1">
      <stop
         style="stop-color:#ff1493;stop-opacity:1"
         offset="0"
         id="stop36064" />
      <stop
         style="stop-color:#9acd32;stop-opacity:1"
         offset="1"
         id="stop36066" />
    </linearGradient>
    <linearGradient
       xlink:href="#grad1"
       id="linearGradient36070"
       x1="87.36869"
       y1="70"
       x2="122.36869"
       y2="70"
       gradientUnits="userSpaceOnUse" />
    <linearGradient
       xlink:href="#color1"
       id="linearGradient36283"
       x1="37.342564"
       y1="70"
       x2="72.342213"
       y2="70"
       gradientUnits="userSpaceOnUse" />
    <linearGradient
       xlink:href="#color2"
       id="linearGradient36289"
       x1="137.65779"
       y1="70"
       x2="172.65744"
       y2="70"
       gradientUnits="userSpaceOnUse" />
  </defs>
  <rect
     style="fill:url(#linearGradient36283);fill-opacity:1;stroke-width:1.05833;stroke-linecap:round;stroke-linejoin:round;-inkscape-stroke:none;paint-order:fill markers stroke;stop-color:#000000"
     id="rect35882"
     width="34.999649"
     height="20"
     x="37.342564"
     y="60" />
  <rect
     style="fill:url(#linearGradient36289);fill-opacity:1;stroke-width:1.05833;stroke-linecap:round;stroke-linejoin:round;-inkscape-stroke:none;paint-order:fill markers stroke;stop-color:#000000"
     id="rect35936"
     width="34.999649"
     height="20"
     x="137.65779"
     y="60" />
  <circle
     style="fill:url(#linearGradient36070);fill-opacity:1;stroke-width:1.05833;stroke-linecap:round;stroke-linejoin:round;-inkscape-stroke:none;paint-order:fill markers stroke;stop-color:#000000"
     id="path35990"
     cx="104.86869"
     cy="70"
     r="17.5" />
</svg>