Style CZML paths thinner and with shade to ground - cesiumjs

Question

I want to display a GPS tracklog in my Cesium application. But I can't get a nice styling for the path working. What I want it to look like:
What it currently looks like:
This is how I style the path currently:
path : {
width : 2,
leadTime : 0,
resolution : 5,
material : {
polylineOutline : {
color : {
rgba : [255, 0, 0, 255]
}
},
},
},
What I want to have:
Thin colored lines without black blurry "outlines" (see second image and compare with first).
A faded area that marks the elevation above ground for the first section of the path.
SOLUTION:
For 1.) I now found a pretty similar solution thanks to emackey:
path : {
show : true,
leadTime : 0,
trailTime : 60,
width : 2.5,
resolution : 1,
material : new Cesium.PolylineGlowMaterialProperty({
glowPower : 15,
taperPower : 0.0001,
color : Cesium.Color.fromBytes(349, 66, 68, 255)
})
}
For 2.) I still haven't found what I'm looking for.

Answer 1

There isn't a built-in effect exactly like that first screenshot you posted from Ayvri (formerly Doarama), but, the most similar built-in thing could be the "tapered line" effect added earlier this year to Cesium:
Here's a demo. Click in the Cesium window and use the arrow keys to steer the aircraft.
These are the path settings from the demo:
path : {
show : true,
leadTime : 0,
trailTime : 60,
width : 10,
resolution : 1,
material : new Cesium.PolylineGlowMaterialProperty({
glowPower : 0.3,
taperPower : 0.3,
color : Cesium.Color.PALEGOLDENROD
})
}