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 Legguards
RecipeMakesReagentsNeedsSkill-up
Turtle Scale Leggings
Turtle Scale LeggingsYellow 230Grey 250
Tough Scorpid LeggingsTaught by Pattern: Tough Scorpid Leggings, requires 220
Tough Scorpid LeggingsYellow 240Grey 260
Supple Scorpid LeggingsTaught by Pattern: Supple Scorpid Leggings, requires 240
Supple Scorpid LeggingsYellow 260Grey 280
Green Dragonscale LeggingsTaught by Pattern: Green Dragonscale Leggings, requires 245
Green Dragonscale LeggingsYellow 265Grey 285
Heavy Scorpid LeggingsTaught by Pattern: Heavy Scorpid Leggings, requires 260
Heavy Scorpid LeggingsYellow 280Grey 300
Charged Scorpid LeggingsTaught by Pattern: Charged Scorpid Leggings, requires 270
Charged Scorpid LeggingsYellow 290Grey 310
Black Dragonscale LeggingsTaught by Pattern: Black Dragonscale Leggings, requires 290
Black Dragonscale Leggings
  • Sewing Machine
Yellow 310Grey 330
Blue Dragonscale Leggings
Blue Dragonscale Leggings
  • Sewing Machine
Yellow 310Grey 330
Spiritcaller KiltTaught by Pattern: Spiritcaller Kilt, requires 300
Spiritcaller Kilt
  • Sewing Machine
Yellow 320Grey 330
Spiritcaller LeggingsTaught by Pattern: Spiritcaller Leggings, requires 300
Unrevealed item #273932
  • Sewing Machine
Yellow 320Grey 330
Spiritcaller PantsTaught by Pattern: Spiritcaller Pants, requires 300
Unrevealed item #273936
  • Sewing Machine
Yellow 320Grey 330
Wildstalker's LegguardsTaught by Pattern: Wildstalker's Legguards, requires 300
Unrevealed item #273900
  • Sewing Machine
Yellow 320Grey 330
Pristine Scorpid LeggingsTaught by Pattern: Pristine Scorpid Leggings, requires 300
Pristine Scorpid Leggings
  • Sewing Machine
Yellow 320Grey 340
Red Dragonscale LeggingsTaught by Pattern: Red Dragonscale Leggings, requires 300
Red Dragonscale Leggings
  • 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.