Write the name of one color in French on one side of each card, using a writing device of the same color. For example, write "vert" in green or scribble the color on the flashcard next to the word. Use the flashcards to memorize the words in French; train your brain to associate the color you see on the flashcard with the word you read.
Start increasing your French color vocabulary by memorizing the basic colors including blue (bleu), red (rouge), green (vert), yellow (jaune), brown (marron), white (blanc) and black (noir). Once you memorize the initial set, add new flashcards with colors such as beige (beige), light blue (bleu clair), orange (orange), pink (rose), purple (violet), silver (argent) and so on. Set goals to keep yourself on track, based on the time you have to dedicate to this task. For example, memorize five new colors every day or every week.
Label items in your household or workplace. Make labels from strips of paper or place your flashcards next to items of the same color. For example, stick the flashcard that says "noir" on a black TV and the flashcard for the color yellow - "jaune" - next to a banana. Keep adding to your French color flashcards and placing them on items you see every day.
Use the colors you have learned in complete sentences. Once you have memorized each color, write a sentence on the corresponding flashcard using the color. Read your sentences aloud. For example, say "Le soleil est jaune," which means "The sun is yellow" in English. Incorporate your new color vocabulary into your French language knowledge base by using it in sentences regularly.