"This black and yellow dog is German."
Translation:Ce chien noir et jaune est allemand.
The basic rule is that in French adjectives come after the noun.
For exceptions, please take a look at this:http://french.about.com/od/grammar/a/adjectives_4.htm
The "root" form of any adjective is masculine singular.
to make it feminine, you add an -e, unless there is already one in masculine.
so, "noir, vert, bleu", take an -e in feminine: noire, verte, bleue
and "jaune, rouge", already having an ending -e in masculine, remain identical in feminine.