Chrome DevTools' internal config when highlighting the element the mouse is over in the Elements panel.

domHighlightConfig.json

{
  "showInfo": true,
  "showRulers": false,
  "showExtensionLines": false,
  "contentColor": {
    "r": 111,
    "g": 168,
    "b": 220,
    "a": 0.66
  },
  "paddingColor": {
    "r": 147,
    "g": 196,
    "b": 125,
    "a": 0.55
  },
  "borderColor": {
    "r": 255,
    "g": 229,
    "b": 153,
    "a": 0.66
  },
  "marginColor": {
    "r": 246,
    "g": 178,
    "b": 107,
    "a": 0.66
  },
  "eventTargetColor": {
    "r": 255,
    "g": 196,
    "b": 196,
    "a": 0.66
  },
  "shapeColor": {
    "r": 96,
    "g": 82,
    "b": 177,
    "a": 0.8
  },
  "shapeMarginColor": {
    "r": 96,
    "g": 82,
    "b": 127,
    "a": 0.6
  }
}