Colored glass in several hues was set into white glass, creating a cute impression.

Literal

White glass [to-に], several-colors [possessive-の] colored-glass [subject-が] entering, cute impression [to-に] finished.

幾色か (いくいろか, 'several colors') uses 幾 ('how many') + 色 ('colors') + か (indefinite). 色ガラス ('colored glass') and 白いガラス ('white glass') are materials vocabulary. 仕上がりました ('finished, turned out') uses 仕上がる for the completed result. かわいらしい ('cute, adorable') is the aesthetic judgment. An artisan/craft description.