What do you mean, "Even my dreams are green"?

This sentence is best understood in the context of the whole poem. Excerpts from the original poem are as follows:

What color do you like?

What color do you like?

I like green,

Because-

The seedlings are green,

The grass is green,

I live in the country,

Even my dreams.

It's also green.

According to the above excerpt, because the author loves the countryside very much, the fields and crops in the countryside are all green. The author loves his parents very much, so his dreams are all green. In essence, it shows the author's deep love for the countryside.