Particle Explosions using Vertex Colours

using UnityEngine;
using System.Collections;

public class VertexColorParticles : MonoBehaviour {

    public int debrisAmount = 10;
    public LayerMask layerMask;
    public Transform debrisParticleTransform;
    private ParticleSystem _debrisParticleSystem;

void Awake()
    {
        _debrisParticleSystem = debrisParticleTransform.GetComponent<ParticleSystem>();
    }

public void CreateDebrisParticles(RaycastHit hit)
    {

        debrisParticleTransform.position = hit.point;
        debrisParticleTransform.rotation = Quaternion.LookRotation(hit.normal);
        Color sampledColor = SampleColour(hit);
        _debrisParticleSystem.startColor = sampledColor;
        _debrisParticleSystem.Emit(debrisAmount);
    }


Color SampleColour(RaycastHit hit)
    {
        Transform objectHit = hit.transform;
        Mesh _mesh = objectHit.GetComponent<MeshFilter>().mesh;

        if (_mesh != null)
        {

            int[] triangles = _mesh.triangles;
            Color[] hitColors = _mesh.colors;

            if (hitColors.Length != 0)
            {
                //Vertex indices
                int t1 = triangles[(hit.triangleIndex*3) + 0];
                int t2 = triangles[(hit.triangleIndex*3) + 1];
                int t3 = triangles[(hit.triangleIndex*3) + 2];

                //Colors
                Color c1 = hitColors[t1];
                Color c2 = hitColors[t2];
                Color c3 = hitColors[t3];

                Vector3 b = hit.barycentricCoordinate;

                var sampleColor = c1*b.x + c2*b.y + c3*b.z;

                return sampleColor;
            }
        }
        return Color.grey;

    }

void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            RaycastHit hit;
            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            if (Physics.Raycast(ray, out hit, Mathf.Infinity, layerMask.value))
            {
                CreateDebrisParticles(hit);
            }

        }
    }

}