We'll be able to load/save palette from/to disk (*.gpl) and store them directly into the svg ?
<linearGradient
inkscape:isPalette="true"
id="My_palette_about_fire" dc:title="My palette about fire" dc:author="Me" dc:licence="CC-BY"
inkscape:collect="always">
<stop id="full_red" dc:title="full red" style="stop-color:#ff0000;stop-opacity:1;" offset="0" />
<stop id="bright_orange" dc:title="bright orange" style="stop-color:#ffdd00;stop-opacity:1;" offset="0.5" />
<stop id="yellow" dc:title="yellow" style="stop-color:#ffff00;stop-opacity:1;" offset="1" />
</linearGradient>
<linearGradient
inkscape:isPalette="true"
id="neutral_colors" dc:title="neutral colors"
inkscape:collect="always"
>
<stop id="full_white" dc:title="full white" style="stop-color:#ffffff;stop-opacity:1;" offset="0" />
<stop id="black" dc:title="black" style="stop-color:#000000;stop-opacity:1;" offset="1" />
</linearGradient>
<solidColor id="defaultbackgroundcolor" solid-color="#ffffff" solid-opacity="0.5" inkscape:coloref="#neutral_colors/#full_white"/>
<solidColor id="textcolorwarning" solid-color="#ff0000" solid-opacity="0.5" inkscape:coloref="#My_palette_about_fire/#full_red" />
</defs>
<g id="" fill="url(#defaultbackgroundcolor)">
<text fill="url(#textcolorwarning)"></text>
...