 D3.merit_order =
   data:
     [
-      {key: 'central_gas_chp'},
+      {key: 'central_gas_chp', color: '#d9d9d9'},
       # {key: 'co_firing_coal'},
-      {key: 'coal_chp'},
-      {key: 'coal_conv'},
-      {key: 'coal_igcc'},
-      {key: 'coal_igcc_ccs'},
-      {key: 'coal_pwd'},
-      {key: 'coal_pwd_ccs'},
-      {key: 'gas_ccgt'},
-      {key: 'gas_ccgt_ccs'},
-      {key: 'gas_conv'},
-      {key: 'gas_turbine'},
-      {key: 'must_run'}, # something's broken here
-      {key: 'nuclear_iii'},
-      {key: 'oil_plant'},
-      {key: 'solar_pv'},
-      {key: 'wind_turbines'},
+      {key: 'coal_chp',        color: '#737373'},
+      {key: 'coal_conv',       color: '#000000'},
+      {key: 'coal_igcc',       color: '#525252'},
+      {key: 'coal_igcc_ccs',   color: '#9ebcda'},
+      {key: 'coal_pwd',        color: '#252525'},
+      {key: 'coal_pwd_ccs',    color: '#8c96c6'},
+      {key: 'gas_ccgt',        color: '#f0f0f0'},
+      {key: 'gas_ccgt_ccs',    color: '#bfd3e6'},
+      {key: 'gas_conv',        color: '#969696'},
+      {key: 'gas_turbine',     color: '#bdbdbd'},
+      {key: 'must_run',        color: '#a1d99b'},
+      {key: 'nuclear_iii',     color: '#fd8d3c'},
+      {key: 'oil_plant',       color: '#7f2704'},
+      {key: 'solar_pv',        color: '#fed976'},
+      {key: 'wind_turbines',   color: '#4292c6'}
     ]
 
   Node: class extends Backbone.Model

      legends.append("svg:rect").
        attr("width", 10).
        attr("height", 10).
        attr("fill", (d, i) => @color(i))
      legends.append("svg:text").
        text((d) -> I18n.t "output_element_series.#{d.get('key')}").
        attr("x", 15).

              attr("text-anchor", "middle").
              attr("class", "axis_label")

      # nodes
      @svg.selectAll('rect.merit_order_node').
        data(@nodes.models, (d) -> d.get('key')).
