Hello n6zs. I don't even remember writing this, nor why. Maybe Duolingo told me my answer without 'got' was wrong. However, it would be difficult to explain the two translations to a French person, compared to: We have got a letter in the mail today = nous avons reçu une lettre.
I assume you have Windows (for Mac, you can always look up the internet). You can't 'add' a circumflex to a letter per se, but you can type variants of Latin vowels using keyboard shortcuts. For ê, hold down the Alt key and type 136 on your keypad. See this page for a complete list of Alt codes: http://www.alt-codes.net/
Color adjectives agree in gender and number with the noun they modify.
Some colors do not change from masculine to feminine, like "rouge" (red) or "jaune" (yellow), because they already have an -e at the end in masculine.
Therefore, "noir", "bleu", "vert", "gris" need an -e to modify a feminine noun and an -s if the noun is plural:
- rouge, rouge (no change), rouge|s, rouge|s
- jaune, jaune (no change), jaune|s, jaune|s
- noir, noir|e, noir|s, noir|es
- bleu, bleu|e, bleu|s, bleu|es
- vert, vert|e, vert|s, vert|es
- gris, gris|e, gris (no change), gris|es
There are exceptions, where the adjective is invariable (no -e in feminine and no -s in plural):
when the color is also the noun of a thing: "marron" (=chestnut), "ardoise" (slate)
when the color is modified: "vert foncé" (dark green), "bleu marine" (navy blue)