Each recipe is orange until its yellow rank and grey from its grey rank. When the ranks differ, it turns green somewhere between the two; the client files give both ranks but not that point. Equal ranks go straight to grey.

Leatherworking: Mail Helmets
RecipeMakesReagentsNeedsSkill-up
Turtle Scale Helm
Turtle Scale HelmYellow 225Grey 245
Tough Scorpid HelmTaught by Pattern: Tough Scorpid Helm, requires 225
Tough Scorpid HelmYellow 245Grey 265
Charged Scorpid HelmTaught by Pattern: Charged Scorpid Helm, requires 240
Charged Scorpid HelmYellow 260Grey 280
Supple Scorpid HelmTaught by Pattern: Supple Scorpid Helm, requires 260
Supple Scorpid HelmYellow 280Grey 300
Heavy Scorpid HelmTaught by Pattern: Heavy Scorpid Helm, requires 270
Heavy Scorpid HelmYellow 290Grey 310
Helm of the Great ChiefTaught by Pattern: Helm of the Great Chief, requires 290
Helm of the Great ChiefYellow 290Grey 310
Black Dragonscale HelmTaught by Pattern: Black Dragonscale Helm, requires 300
Black Dragonscale Helm
  • Sewing Machine
Yellow 320Grey 340
Blue Dragonscale HelmTaught by Pattern: Blue Dragonscale Helm, requires 300
Blue Dragonscale Helm
  • Sewing Machine
Yellow 320Grey 340

From the Forever beta client files, build 1.60.1.70630: the SkillLine, SkillLineAbility, TradeSkillCategory, SpellReagents, SpellEffect, SpellTotems, SpellCastingRequirements and ItemEffect tables.