CASE 1, original layer tree
{
  "bounds": [800, 600],
  "children": [
    {
      "bounds": [800, 600],
      "contentsOpaque": true,
      "drawsContent": true,
      "children": [
        {
          "children": [
            {
              "position": [50, 50],
              "bounds": [100, 100],
              "contentsOpaque": true,
              "drawsContent": true,
              "backgroundColor": "#0000FF"
            },
            {
              "position": [130, 130],
              "bounds": [100, 100],
              "drawsContent": true
            }
          ]
        }
      ]
    }
  ]
}
CASE 2, change color of "inner" to red
{
  "bounds": [800, 600],
  "children": [
    {
      "bounds": [800, 600],
      "contentsOpaque": true,
      "drawsContent": true,
      "children": [
        {
          "children": [
            {
              "position": [50, 50],
              "bounds": [100, 100],
              "contentsOpaque": true,
              "drawsContent": true,
              "backgroundColor": "#0000FF"
            },
            {
              "position": [130, 130],
              "bounds": [100, 100],
              "drawsContent": true,
              "repaintRects": [
                [10, 10, 50, 50]
              ]
            }
          ]
        }
      ]
    }
  ]
}