Equipment Item Text Color

You're pretty close.
It's:

• Gray = Below average total stats.
  
• White = 0-5 total stats above average. (And no scrolls landed yet)
  
• Orange = 0-5 total stats above average and at least 1 successful scroll landed.
  
• Blue = 6-22 total stats above average.
  
• Purple = 23-39 total stats above average.
• Gold/Yellow = 40 or more total stats above average.

HP and MP are I believe divided by 5.

Edit: I made a small mistake and edited post to fix, thanks Ainz for pointing it out.

Also UnknownCode the reason you saw a purple clean scar helm is because those roll a lot of stats, so if you get a lucky roll (including high defense and magic defense) you can get more than 23 stats above average on a clean helm.

 

I'm 99% certain you can get a gray item even after landing a scroll, or am I misinterpreting your description?

 

You're 100% correct, I keep mixing that up, will update original post.

Spoiler: Old Post

• Gray = Below average total stats. (And no scrolls landed yet)
  
• White = 0-5 total stats above average. (And no scrolls landed yet)
  
• Orange = Below average or 0-5 total stats above average and at least 1 successful scroll landed.
  
• Blue = 6-22 total stats above average.
  
• Purple = 23-39 total stats above average.
• Gold/Yellow = 40 or more total stats above average.

Spoiler: Fixed Post

• Gray = Below average total stats.
  
• White = 0-5 total stats above average. (And no scrolls landed yet)
  
• Orange = 0-5 total stats above average and at least 1 successful scroll landed.
  
• Blue = 6-22 total stats above average.
  
• Purple = 23-39 total stats above average.
• Gold/Yellow = 40 or more total stats above average.