What do the colors mean?

In Final Surge, workout completion is color-coded to indicate how a workout was performed. Green indicates a workout completed as planned (80-120% of planned duration/distance), while yellow signifies a workout that was either under or over-performed (50-79% or 121-150% of planned duration/distance). Red indicates a workout was not completed, or completed significantly under or over the planned duration/distance (under 50% or over 150%). Grey represents future workouts or workouts with no planned duration/distance