When I was a child ,I enjoyed making clay figurine,then writing it with kinds of colors.I felt very happy when watching my beautiful craft.Now I can also have a similar good time in ffxiv.
In Final Fantasy 14, you will notice that when you are crafting, the colors of the synthesis may change as you go through your craft. They may also spark or even go “unstable”, which causes an elemental swirl to occur around your synthesis.
Sparking indicates that the synthesis is not very stable and is likely to go unstable; the more sparks, the closer it is to instability. When an item goes unstable, if you fail it, sometimes the item will lose a ton of quality or even fail outright, making this a risky state to be in.
When you choose a synthesis option when it is red, it is most likely to fail, but if you are successful, you will get a larger than normal increase in quality and you are happy though your ffxiv gil is decrease. However, the developers have stated that a synthesis which changes colors a lot, really helps the chance to create an HQ item.
As a result, colors and sparks are not necessarily good or bad. If you are crafting a synthesis that is very high level compared to you, or you just want to be successful, hoping the color changes or it settles down. On the other hand, if you want to make an HQ item, you need a high quality score and a lot of color changes to get HQ items reliably.