message: Added colorspace attribute for reflectivity/edge_color.
diff: <nodedef name="ND_conductor_brdf" node="conductor_brdf" type="BSDF" bsdf="R" nodegroup="pbr"
  doc="A reflection BSDF node based on a microfacet model and a Fresnel curve for conductors/metals.">
  <input name="weight" type="float" value="1.0" uimin="0.0" uimax="1.0"/>
  - <input name="reflectivity" type="color3" value="0.944, 0.776, 0.373"/>
  - <input name="edge_color" type="color3" value="0.998, 0.981, 0.751"/>
  + <input name="reflectivity" type="color3" value="0.944, 0.776, 0.373" colorspace="lin_rec709"/>
  + <input name="edge_color" type="color3" value="0.998, 0.981, 0.751" colorspace="lin_rec709"/>
  <input name="roughness" type="vector2" value="0.0, 0.0"/>
  <input name="normal" type="vector3" defaultgeomprop="Nworld"/>
  <input name="tangent" type="vector3" defaultgeomprop="Tworld"/>
  -->
  <nodedef name="ND_artistic_ior" node="artistic_ior" type="multioutput" nodegroup="pbr"
  doc="Converts the artistic parameterization reflectivity and edge_color to complex IOR values.">
  - <input name="reflectivity" type="color3" value="0.944, 0.776, 0.373"/>
  - <input name="edge_color" type="color3" value="0.998, 0.981, 0.751"/>
  + <input name="reflectivity" type="color3" value="0.944, 0.776, 0.373" colorspace="lin_rec709"/>
  + <input name="edge_color" type="color3" value="0.998, 0.981, 0.751" colorspace="lin_rec709"/>
  <output name="ior" type="vector3"/>
  <output name="extinction" type="vector3"/>
  </nodedef>
  