Floating Health Bars

I am attempting to create floating health bars for moving game objects. After a fair amount of Googling, I finally found a decent enough example to start with. The example I found uses GUI.DrawTexture with a normal Texture object (not a GUITexture or Texture2D). Here is the relevant code for the script I have attached to my game objects:

 public class Creep : MonoBehaviour
 {
     public Texture barBG;
     public Texture barFG;
     private Vector3 barPos;
     private float yOffset = 2.2f;
     private float barWidth = 256.0f;
     private float barHeight = 32.0f;
     private float barScale = .25f;
     
     public float maxHealth = 10f;
     public float health;
     private float healthPercent;
     
     private float healthBar;
     private Color highHealth = new Color(7.0f / 255.0f, 161.0f / 255.0f, 7.0f / 255.0f);
     private Color mediumHealth = new Color(161.0f / 255.0f, 157.0f / 255.0f, 7.0f / 255.0f);
     private Color lowHealth = new Color(161.0f / 255.0f, 42.0f / 255.0f, 7.0f / 255.0f);
     private Color barColor;
     
     void Start()
     {
         barWidth *= barScale;
         barHeight *= barScale;
         health = maxHealth;
         healthPercent = health / maxHealth;
     }
     
     void Update()
     {
         barPos = Camera.main.WorldToScreenPoint(new Vector3(transform.position.x, transform.position.y + yOffset, transform.position.z));
         barPos.y = Screen.height - barPos.y;
 
         healthPercent = health / maxHealth;
         if (healthPercent > 0.50f)
         {
             barColor = Color.Lerp(mediumHealth, highHealth, (healthPercent - 0.50f) / 0.50f); // want 1.00 to be 100%, want .50 to be 0%
         }
         else
         {
             barColor = Color.Lerp(lowHealth, mediumHealth, healthPercent / 0.50f); // want .50 to be 100%, want 0.00 to be 0%
         }
     }
     
     void OnGUI()
     {
         GUI.color = barColor;
         GUI.DrawTexture(new Rect(barPos.x - barWidth/2, barPos.y, barWidth, barHeight), barBG, ScaleMode.StretchToFill, true, 0.0f);
         GUI.DrawTexture(new Rect(barPos.x - barWidth/2, barPos.y, barWidth * healthPercent, barHeight), barFG, ScaleMode.ScaleAndCrop, true, 0.0f);
     }
 }

This code does work and it accomplishes most of what I wish to accomplish, but I'm having trouble getting the colors to appear as I would like them to. The colors representing the RGB values I'm using should be bright and vivid. If I create a GUITexture in the game and set the same colors, the green looks like this:

But in-game, using the same texture file (but not as a GUITexture), it looks like this:

Is this because I'm using the GUI.color variable? Is there anyway to brighten it to display the intended RGB color value?

Also, if anyone has any recommendations for a better approach to implementing floating health bars, I'd love to hear it. I tried using GUITextures and Texture2D, but didn't have much luck with them. I'm still new to Unity and its API though, so I would appreciate any advice.