How to change object color of an instant mesh shader material without tinting the texture?

Questions
1

Setting new THREE.Color().setHSL(Math.random(), 0.75, 0.75) to the color causes the texture’s tint to change with it. Is it possible to keep the texture color/tint untouched, preserving it’s alpha, while changing only the object’s color?

material = new THREE.MeshToonMaterial( {
    color: new THREE.Color().setHSL(Math.random(), 0.75, 0.75),
    map: assets.textures['atlas'],
    gradientMap: assets.textures['tone-3'],
    onBeforeCompile: ( shader ) => {
        shader.uniforms.atlasSize = { value: atlasSize };
        shader.uniforms.tile = { value: new THREE.Vector2( 1, 0 ) };
        shader.vertexShader = `
        attribute vec2 tile;
        varying vec2 vTile;
        ${shader.vertexShader}
        `.replace(
            `#include <uv_vertex>`,
            `
            vTile = tile;
            #include <uv_vertex>`
        );				
            shader.fragmentShader = `
                uniform vec2 atlasSize;
                varying vec2 vTile;
                ${shader.fragmentShader}
                `.replace(
                `#include <map_fragment>`,
                `
                vec2 tile = vTile;
                vec2 mUV = vMapUv;
                vec2 centerUV = ((mUV - 0.5) * vec2(2., 1.) + vec2(0.5, 0.)) * PI/2.;
                mUV = centerUV + 0.5;
                vec2 atlasTile = 1. / atlasSize;
                
                mUV = clamp((mUV + tile) * atlasTile, vec2(0.), vec2(1.));

                vec4 sampledDiffuseColor = texture( map, mUV );
				
                vec2 absUV = abs(centerUV);
				
                float cutoff = 1. - step(0.5, max(absUV.x, absUV.y));
                diffuseColor = vec4( mix( diffuse, sampledDiffuseColor.rgb, sampledDiffuseColor.a * cutoff), opacity );
                `
            );
        }
    } );

From prisoner849’s codepen: https://codepen.io/prisoner849/full/abrdgVW