Apex chart problem

I have struggling with configuring the colors in apex chart. I have two temperature series (line charts) which show temprature in two different parts of the house. I also want to indicate on chart when heater/air conditioner is on and using a column of fixed height to show the state (column is 0 height if it is off).
Now I am not able to get the colors to work. Here is what I am looking to do -
1. Both temperature series should show a color gradient between blue and red. Blue being cold, and red being hot. the gradient should change from blue to red between 40 and 80.
2. The column should change the color to red when heater is on, and blue when air conditioner is on. For this i created a sensor whose value changes to 70 if a/c is on and 71 if heater is on. (I want these values to be very close to each other so column shouldn’t look different height)

Is it possible and if yes, how do I do it ? Here is my apex chart yaml

type: grid
square: false
columns: 1
cards:
  - type: thermostat
    entity: climate.thermostat
    features:
      - type: climate-hvac-modes
        hvac_modes:
          - 'off'
          - heat
          - cool
          - heat_cool
    show_current_as_primary: true
  - type: custom:apexcharts-card
    header:
      show: true
      title: Temprature
      show_states: true
      colorize_states: true
    graph_span: 2d
    apex_config:
      grid:
        show: true
        strokeDashArray: 0
        borderColor: '#383838'
        position: back
        xaxis:
          lines:
            show: true
        yaxis:
          lines:
            show: true
    yaxis:
      - id: tempaxis
        decimals: 0
        min: '|-1|'
        max: '|+1|'
      - id: hvacon
        opposite: true
        decimals: 0
        min: 0
        max: 340
        show: false
    series:
      - entity: sensor.thermostat_current_temperature
        curve: smooth
        name: Living room Temp
        fill_raw: last
        color: ff7100
        yaxis_id: tempaxis
        stroke_width: 2
        group_by:
          func: avg
          duration: 1hr
      - entity: sensor.masterbedroom_am2301_temperature
        curve: smooth
        name: Bedroom Temp
        fill_raw: last
        yaxis_id: tempaxis
        color: ffa600
        stroke_width: 2
        group_by:
          func: avg
          duration: 1hr
      - entity: sensor.hvac_on
        curve: smooth
        fill_raw: last
        yaxis_id: hvacon
        name: HVAC on
        stroke_width: 1
        color: red
        type: column
        show:
          legend_value: false
          name_in_header: false
          in_header: false
          offset_in_name: false
        group_by:
          func: max
          duration: 5min