As I understand it:

White - High success, low quality
Yellow - Average success, Average quality
Red - Low success, low quality
Pulsating - Low success, high quality

Standard synth - Average quality, success, progress and durability.
Rapid - High progress, low success, no quality. If success, no durability loss. If fail, high durability loss.
Careful - High quality, low progress, low durabiliy, average success.


When leveling, my set up is thus:

Abilities:

Culmination
Byregot's Blessing
Perfection
By the Books
(Another progress ability)

I start with Culmination and Rapid, get about 30-40% progress. Use Byregot's Blessing and grind out Careful. At some point during BB if I get a gold or prismatic I use Perfection and get a nice 100+ to Quality. Then I grind Careful until my Durability is in the teens. Thanks to my two progress abilities and Culmination+Rapid I only ever need to earn about 10 to 20 progress during any synth to know it'll be a success.

On synths over my level I can push ~300 Quality. Those below about ~500.

In short: Wait on red, careful on gold, careful on prismatic if you feel comfortable with you progress/durability.

Use your abilities wisely and remember, for each craft you level, each one thereafter is significantly easier.