"He is blue and white" 的英语表达方式是 "He is wearing blue and white."

"Wearing" 是动词，表示穿着或佩戴某物的意思。这种表达方式比较常见，通常用来描述人或动物的外表颜色。
例句：

The bird is wearing blue and white feathers.
He is wearing a blue and white striped shirt.

而 "He is blue and white" 也可以理解为 "He has blue and white color"
例句：

Blue and white are the colors of the Chinese flag.
The marble statue is blue and white.

来源上, "blue and white" 是颜色词组， blue 是蓝色，white 是白色， 当这两种颜色混合时，就会有蓝白色。