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.

Enchanting: Wizard Oils
RecipeMakesReagentsNeedsSkill-up
Minor Wizard OilTaught by Unrevealed item #20751Taught by Formula: Minor Wizard Oil, requires 5
Minor Wizard OilQuantity not confirmed
  • Runed Copper Rod
Yellow 30Grey 65
Minor Mana OilTaught by Formula: Minor Mana Oil, requires 150
Minor Mana OilQuantity not confirmed
  • Runed Silver Rod
Yellow 160Grey 180
Lesser Wizard OilTaught by Formula: Lesser Wizard Oil, requires 200
Lesser Wizard OilQuantity not confirmed
  • Runed Golden Rod
Yellow 210Grey 230
Lesser Mana OilTaught by Formula: Lesser Mana Oil, requires 250
Lesser Mana OilQuantity not confirmed
  • Runed Truesilver Rod
Yellow 260Grey 280
Wizard OilTaught by Formula: Wizard Oil, requires 275
Wizard OilQuantity not confirmed
  • Runed Truesilver Rod
Yellow 285Grey 305
Brilliant Mana OilTaught by Formula: Brilliant Mana Oil, requires 300
Brilliant Mana OilQuantity not confirmed
  • Runed Arcanite Rod
Yellow 310Grey 330
Brilliant Wizard OilTaught by Formula: Brilliant Wizard Oil, requires 300
Brilliant Wizard OilQuantity not confirmed
  • Runed Arcanite Rod
Yellow 310Grey 330

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