gradate
/grəˈdeɪt/verb
1- pass or cause to pass by gradations from one shade of colour to another（使）色彩逐渐转化：
no obj. the black background gradated toward a dark purple.黑色的背景渐渐变成了暗紫色。
1.1
- with obj. arrange in steps or grades of size, amount, or quality（按照尺寸、数量或质量）顺次排列：
as adj. gradated the Temple compound became a series of concentric circles of gradated purity.坦普尔化合物变成了一串按纯度渐次排列的同心圆。
词源
mid 18th cent.: back-formation from GRADATION.