Photoshop Scripting select contents of a layer & color - photoshop

Question

Using a javascript script in Photoshop 2022 (v 23.0.1), I am trying to change the color of a single item in one of my layers. I can access the layer, but I cannot change the color of it's contents.
var document = activeDocument;
var groupA = document.layers["Group"];
var layerA = groupA.layers["Layer In Group"];
var layerB = groupA.layers["Clipping Mask for layerA"];
The layerA contains a single item which is colored white. I'd like to change it's color.
I assume I need to select the contents of that layer, then apply a color to it. But I'm not sure this is the best way to do this.
I could also add a clipping mask for that layer, then fill that with color. Would this be easier/better?
Ideally I'd like to change it using a hex color code, but any way I can change it would be fine.
UPDATE: I was able to solve the problem by making the layer the activeLayer in the document.
// set the active layer to the layer requiring fill color
document.activeLayer = layerB;
// getBodyFillColor() is my method that returns the correct color
var color = getBodyFillColor();
// Once I set the active layer, it's automatically the selection layer?? (not sure how this works)
document.selection.fill(color);

Answer 1

You could just fill with a colour:
// Fill colour
var myRGBCol = [255, 0, 128]; //define your colour here
var col = new SolidColor;
col.rgb.red = myRGBCol[0];
col.rgb.green = myRGBCol[1];
col.rgb.blue = myRGBCol[2];
var blend = ColorBlendMode.NORMAL; // Normal
var op = 100; // opacity
document.selection.fill(col, blend, op, false);