What is a antonym for the word blue?

There isn't one single perfect antonym for "blue" because it has multiple meanings. Here are some options depending on the context:

For the color blue:

* Red (a contrasting color on the color wheel)

* Yellow (another contrasting color on the color wheel)

* Green (often used in contrast to blue, especially in terms of feeling)

* Orange (also a contrasting color)

For the feeling of sadness:

* Happy

* Joyful

* Cheerful

* Elated

* Content

For the feeling of being "blue" in the sense of "melancholy":

* Cheerful

* Optimistic

* Hopeful

* Upbeat

For the sense of "blue" as a color:

* Any other color

It's important to consider the specific meaning of "blue" in the context you're using it to find the most appropriate antonym.