我有一个关于Chart.js的问题。我正在使用一个包含2组数据（2行）的折线图，当我将鼠标悬停在数据上时，它会显示“图例”。图例中有2个可以着色的框。我可以更改框的背景颜色，但没有问题，但当我更改颜色时，它会应用于两个框。我如何单独设置框的颜色？谢谢。

<canvas
    class="ex-line-graph"
    width="1200" height="1200"
    data-chart="line"
    data-scale-start-value="0"
    data-scale-step-width ="100"
    data-scale-steps ="4"
    data-point-fill-color = "RGBA( 255,28,221,.3)"
    data-scale-line-color="transparent"
    data-scale-grid-line-color="rgba(255,255,255,.05)"
    data-scale-font-color="#a2a2a2"
    data-labels="         ['April','May','June','July','August','September','October','November','December        ','January','February','March']"
    data-value="[{ fillColor: 'RGBA( 28,168,221,.3)', strokeColor:      
    '#1CA8DD', label:'Data', data: [151, 154, 173, 169, 176,161,0,0,0,0,0,0]}, {fillColor: 'RGBA(37,40,48,.0)', strokeColor: 'rgba(255,255,255,1)', label :'Target', data: [200, 200,200,200,200, 200,200,200,200, 200,200,200] }]">
  </canvas>