une femme en colère

is the standard translation for an angry woman.

Reference

The other form is rarely used (as confirmed by the ngram)

• colère is a noun that means anger

• être en colère means to be angry

• se mettre en colère means to get angry

• mettre quelqu’un en colère means to make somebody angry

You can say both but the first one is old:

1. Adjt. Pop. et vieilli. Prompt à s’irriter ; d’un caractère violent. Un homme colère. Des enfants colères. Par méton. Il est d’humeur colère.

from Dictionnaire de l’Académie

II.− Emploi adj.

A.− [En parlant d’une pers.] Que son caractère porte à se mettre facilement en colère :

1. Je me suis aperçu depuis longtemps que les gens colères soutiennent toujours qu’ils ne sont pas colères, que ceux qui ont peur, disent souvent qu’ils n’ont pas peur; … Napoléon Ier, Lettres à Joséphine,1806, p. 119.

source

Colère is not an adjective in everyday French (at least in France), it’s a noun. It means anger, not angry.

There is no adjective with exactly the same usage as angry. What comes closest is the phrase en colère (literally: in a state of anger). Another adjective that’s often used in everyday life is énervé, but its meaning is a little different, leaning more towards nervous, especially in literary use (in colloquial speech, énervé does mean angry).

The adjective colère has fallen into disuse, and means prone to anger (as opposed to angry right now). Nowadays, we would say colérique or coléreux.

Protesters sometimes use “en colère” to say they’re angry about a particular social issue. (I think the French Federation of angry bikers popularized this formulation.) They would not describe themselves as colères (quick-tempered); en colère here suggests rightful wrath.