Title of ApexCharts

Configuration Frontend
1

Hello,

I wrote the following code:

type: entities
entities:
  - type: custom:text-divider-row
    text: Stazione meteo di Civitavecchia
    text-divider-color: var(--secondary-text-color)
    card_mod:
      style: |
        .text-divider span {
          color: #8Ab4f8 !important;
          font-size: 14px !important;
          }
  - type: custom:stack-in-card
    mode: horizontal
    cards:
      - type: custom:apexcharts-card
        chart_type: line
        graph_span: 12h
        apex_config:
          chart:
            height: 130px
        show:
          last_updated: false
        header:
          show: true
          title: Temperatura in °C
          show_states: false
        series:
          - entity: sensor.meteonetwork_temp
            curve: smooth
            stroke_width: 3
            color: '#FFFF00'
            show:
              extremas: true
      - type: custom:apexcharts-card
        chart_type: line
        graph_span: 12h
        apex_config:
          chart:
            height: 130px
        show:
          last_updated: true
        header:
          show: true
          title: Umidità
          show_states: false
          colorize_states: false
        series:
          - entity: sensor.meteonetwork_rh
            curve: smooth
            stroke_width: 3
            color: '#00ffff'
            show:
              extremas: true

I have two titles for every apexcharts, so could you tell me how to change the title color of this graphs?