Significance of color change as skills/vocabulary decay
I have completed both the French and Spanish skill trees, but I have only continued to do a small amount of daily work on each for the last week due to a busy schedule.
As the skills in the lessons decay, the skill bars begin to empty, and also change from gold to another color (turquoise, blue, light green) on both the iPad app and on the website.
Although I searched, I couldn't find any description of the meanings of a particular color. Do they indicate the degree of decay, the nature of the decay, or do they have any significance at all?
Any insights would be appreciated!