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.

Alchemy: Draughts
RecipeMakesReagentsNeedsSkill-up
Draught of TonguesTaught by Unrevealed item #2556
Unrevealed item #2460Yellow 100Grey 140
Draught of Water Breathing
Draught of Water BreathingYellow 120Grey 160
Draught of Water WalkingTaught by Unrevealed item #288206
Draught of Water WalkingYellow 190Grey 230
Potion of Predatory SensesTaught by Recipe: Potion of Predatory Senses, requires 195
Potion of Predatory SensesYellow 200Grey 205
Revealing DraughtTaught by Unrevealed item #250362
Unrevealed item #250326Yellow 205Grey 210
Draught of Detect Lesser InvisibilityTaught by Recipe: Elixir of Detect Lesser Invisibility, requires 195
Draught of Detect Lesser InvisibilityYellow 215Grey 255
Catseye Draught
Catseye DraughtYellow 220Grey 260
Draught of Greater Water Breathing
Draught of Greater Water BreathingYellow 230Grey 270
Draught of Detect Undead
Draught of Detect UndeadYellow 245Grey 285
Draught of Dream VisionTaught by Recipe: Draught of Dream Vision, requires 240
Draught of Dream VisionYellow 255Grey 295
Draught of Detect Demon
Draught of Detect DemonYellow 265Grey 305

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