General:
* Je suis rouge. (This is the most straightforward translation.)
More specific:
* J'ai le visage rouge. (I have a red face.) - This emphasizes the redness of your face, perhaps due to embarrassment or heat.
* Je suis rougissant. (I am blushing.) - This implies a specific type of redness, usually associated with embarrassment or shyness.
You could also use other phrases depending on the situation, such as:
* Je suis en colère. (I am angry.)
* Je suis énervé. (I am upset.)
* Je suis timide. (I am shy.)
The best translation for "I am red" will depend on the context and the specific meaning you want to convey.