Time varying color for wall object

1. A concise explanation of the problem you're experiencing.

For a wall geometry. when I try to add a callback property to the material, it fails.

2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.
var entities = ;
for (var idx =0; idx<IDList.length; idx++) {
        var colorCallbackFunction = (function(){
            var ID = IDList[idx];
            return function(time,result) {
                var value = sampledData.getValue(time);
                if (value) {
                   // Value of 120 and above would be red;
                   // value of zero and below are blue
                    var HSLValue = 0.65 - 0.65 / 120.0 * value;
                    HSLValue = Math.min(Math.max(HSLValue, 0), 0.65);
                    return Cesium.Color.fromHsl(HSLValue, 1, 0.5, 0.5);
                } else {
                    return Cesium.Color.RED.withAlpha(0.5);
     // similar stuff for positionCallbackFunction
var entity = {
            name: "ID: " + IDList[idx],
            wall: {
                positions: new Cesium.CallbackProperty(positionCallbackFunction, false),
                material: new Cesium.CallbackProperty(colorCallbackFunction, false) // This would fail
                // material: Cesium.Color.RED.withAlpha(0.5) // this is OK; but everything is a fixed color then.

Later I add the entities to the viewer.

If I choose the constant color everything works just fine;

However, if I set the colorCallbackFunction I get the following error:
An error occurred while rendering. Rendering has stopped.
TypeError: materialProperty.getType is not a function
TypeError: materialProperty.getType is not a function
    at Function.MaterialProperty.getValue (http://localhost:8080/cesium.js:29482:37)
    at DynamicGeometryUpdater.update (http://localhost:8080/cesium.js:168392:45)
    at DynamicGeometryBatch.update (http://localhost:8080/cesium.js:156631:27)
    at GeometryVisualizer.update (http://localhost:8080/cesium.js:156834:36)
    at DataSourceDisplay.update (http://localhost:8080/cesium.js:154996:37)
    at Viewer._onTick (http://localhost:8080/cesium.js:247135:49)
    at Event.raiseEvent (http://localhost:8080/cesium.js:2361:30)
    at Clock.tick (http://localhost:8080/cesium.js:54620:21)
    at CesiumWidget.render (http://localhost:8080/cesium.js:227663:43)
    at render (http://localhost:8080/cesium.js:227039:32)

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.
I want to have a moving wall with changing color showing certain properties

4. The Cesium version you're using, your operating system and browser.

"cesium": "^1.42.1",

Any takers?

Any takers?

Something like

sampledcolor = new Cesium.SampledProperty(Cesium.Color);
ent.material = new Cesium.ColorMaterialProperty(sampledcolor)

then lots of

sampledcolor.addSample(time, color);

where color is a different Cesium.Color for each different time

works for me, but I guess it depends on your use case

Cheers -Terry

Thanks Terry.

This resolved the issue.

really appreciate it.