Is There Any Logic to Synthesis?

[Raldo]

There are few general synthesis guides out there because much of the information we'd like to know, is still debated amongst those that proclaim themselves as professional crafters. Then when someone does write up a decent guide, SE goes and changes the system again.

The Stability of Synthesis Materials
The stability of synthesis materials is represented by the color of the glowing light displayed onscreen while crafting. Each command executed has an effect on stability.

When the glowing light is white, the materials are extremely stable, and the chances of success of synthesis commands are increased. The light may also turn from yellow, to red, to multiple colors flashing rapidly. Though these states represent progressively lower chances of success when executing commands, they also indicate times at which the quality of the synthesis can most easily be enhanced, therefore increasing the likelihood of creating a high-quality item.

Source (at the very bottom)

To me, that means...

White, Yellow, Red, Flashing/Rainbow/Prismatic (call it whatever you like)
Highest Chance of Success <---------> Lowest Chance of Success
Lowest Quality Gains <---------------> Highest Quality Gains (upon success)

There are some people who argue with that conclusion, but that's how I read it.

That also means that no specific action is tailored to any specific color, which would explain why you were having trouble figuring out what the colors meant. There is no way to guarantee a successful action, so the best you can do is stack the crafting stats and hope for the best. The most important thing you can do is equip the right abilities, and know when it's best to use which actions and abilities. For the most part, this knowledge is just gained through the experience of trial and error.

There's a great deal more to know about crafting, but I'll either leave you to figure that out for yourself, or wait until you ask something else specific.

Here is a potentially helpful "general synthesis guide" that I wrote up some time ago. There have been some changes since I wrote that guide, so a small number of those things are no longer valid.