flock richtree is GPL, so not suitable for use.

disruptive innovations richtree doesn't appear to have a release.

This mostly works; it's based on the gecko code so is MPL; as such it's up here.

Doesn't support atoms, only supports JS views (i think). 
Hierarchy lines not dotted or quite joining twisties.
Editing not supported.
Sorting not supported (as can only sort on RDF, and templates not supported)

treecols and treecchildren as normal tree; addition of <richtreecells> element
with templates for cells. each column may have a <richtreecell> with colid matching the column's id.
The content of the <richtreecell> is used as a template for rendering the tree cell.
The view.getCellText() and view.getCellValue() values are written to the attributes named by text-attribute and value-attribute of the children of the richtreecell.

This also uses a <colorswatch> which is an embedded svg rect, using its value attribute for the fill colour; so the net effect is that the svg is determined by the values in the tree's data.

<richtree id="richElementList" flex="1" enableColumnDrag="true" >
  <treecols>
    <treecol id="runner" label="Runner" flex="2" persist="width ordinal hidden"/>
    <splitter class="tree-splitter"/>
    <treecol id="city" label="Home City" flex="2" persist="width ordinal hidden"/>
    <splitter class="tree-splitter"/>
    <treecol id="starttime" label="Start Time" flex="1" persist="width ordinal hidden"/>
    <splitter class="tree-splitter"/>
    <treecol id="endtime" label="End Time" flex="1" persist="width ordinal hidden"/>
  </treecols>
  
  <richtreecells>
    <richtreecell colid="city">
      <colorswatch text-attribute="value" width="20" height="20"/>
    </richtreecell>
    <richtreecell colid="city" mode="edit">
      <colorpicker/>
    </richtreecell>  
  </richtreecells>
  <richtreechildren/> 
</richtree>