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.

Engineering: Scopes
RecipeMakesReagentsNeedsSkill-up
Crude Scope
Crude Scope
  • Arclight Spanner
Yellow 90Grey 120
Standard Scope
Standard Scope
  • Arclight Spanner
Yellow 135Grey 160
Ornate Spyglass
Ornate SpyglassYellow 160Grey 185
Accurate ScopeTaught by Schematic: Accurate Scope, requires 180
Accurate Scope
  • Arclight Spanner
  • Gyromatic Micro-Adjustor
Yellow 200Grey 220
Deadly ScopeTaught by Schematic: Deadly Scope, requires 210
Deadly Scope
  • Blacksmith Hammer
  • Arclight Spanner
  • Anvil
Yellow 230Grey 250
Sniper ScopeTaught by Schematic: Sniper Scope, requires 240
Sniper Scope
  • Blacksmith Hammer
  • Arclight Spanner
  • Anvil
Yellow 260Grey 280
SAF-T Ultra Precision ScopeTaught by Schematic: SAF-T Ultra Precision Scope, requires 300
SAF-T Ultra Precision Scope
  • Arclight Spanner
  • Gyromatic Micro-Adjustor
  • Anarchist's Workbench
Yellow 310Grey 325
Biznicks 247x128 AccurascopeTaught by Schematic: Biznicks 247x128 Accurascope, requires 300
Biznicks 247x128 Accurascope
  • Blacksmith Hammer
  • Arclight Spanner
  • Anvil
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.