docs: public static boolean blockColourMatches(IBlockState bs, List<Colour> allowedColours)
      {
          for (IProperty prop : bs.getProperties().keySet())
          {
              if (prop.getName().equals("color") && prop.getValueClass() == net.minecraft.item.EnumDyeColor.class)
              {
                  // The block in question has a colour, so check it is a specified one:
                  net.minecraft.item.EnumDyeColor current = (net.minecraft.item.EnumDyeColor)bs.getValue(prop);
                  for (Colour col : allowedColours)
                  {
                      if (current.getName().equalsIgnoreCase(col.name()))
                          return true;
                  }
              }
          } 
          return false;
      }