赤くて

red and

→ 赤い
red + Adverbial/continuative form of an i-adjective + Te-form (conjunctive)
adjective Rare #39,935
red and The て-form of 赤い, used to connect this adjective to another word or clause.
JA: 赤くてきれいな花ですね。
EN: It’s a beautiful red flower.
Forms of 赤い
赤い赤く赤くて

この木は赤くて美しい

This tree is red and beautiful.

この花は赤くてきれいです

This flower is red and beautiful.

この木は赤くて綺麗

This tree is red and beautiful.

トマト赤くて深い新鮮な太陽

The tomato is deep red—a fresh sun.

— イル・ポスティーノ (1994)