gradate
1. [ verb ] arrange according to grades
Examples:

"These lines are gradated"

Related terms: arrange gradation
2. [ verb ] pass imperceptibly from one degree, shade, or tone into another
Examples:

"The paint on these walls gradates but you don't see it"

Related terms: change
Similar spelling:   graduate
  graduated
  gradatory
  gradation
  graded
  gratitude
  gratuity