Guild Wars 2

To infuse a non colored Spinal Blade backpieces (Tempered Spinal Blades) you need 1 Tempered Spinal Blade, 250 Glob of Ectoplasm, 1 Gift of Ascension, 1 Glob of Coagulated Mists Essence.
To infuse the colored Spinal Blade backpieces (Static, Dynamic, Synergetic Tempered Spinal Blades) you only need: 1 [Type] Tempered Spinal Blades + 10 Pile of Crystalline Dust + 1 Glob of Coagulated Mist Essence + 1 Gift of Ascension in Mystic Forge

So if you infuse it before choosing a color you wasted 250 ectos and I came to the conclusion this must be a bug. If its not I want my stack of ectos back, I infused mine before the recipes for colored Tempered Spinal Blades became available.

It’s possible they reduced the requirements for the colored pack because it takes more materials to make, so they might have felt it was more fair to have a less demanding infusion cost. (They may have anticipated power cores being more rare or something)

But eh. Possibly not! Anyway, it would be nice if it was a bug and that you could get your ectos back.