Cesium3DTileColorBlendMode

When REPLACE or MIX are used and the source color is a glTF material, the technique must assign the _3DTILESDIFFUSE semantic to the diffuse color parameter. Otherwise only HIGHLIGHT is supported.

A feature whose color evaluates to white (1.0, 1.0, 1.0) is always rendered without color blending, regardless of the tileset's color blend mode.

"techniques": {
  "technique0": {
    "parameters": {
      "diffuse": {
        "semantic": "_3DTILESDIFFUSE",
        "type": 35666
      }
    }
  }
}