In the seventeenth century you could use the word drab as a noun in a sentence. You could have said, "His companions were drabs." It wouldn't have been a very nice thing to say. Noah Webster's 1828 dictionary lists this meaning as the first definitions of the word, a low sluttish woman. The etymology of the word suggests it came into English from Gaelic "drabog" meaning "a dirty woman."
Our modern meaning of drab, simply a dull color, used to imply the color of undyed cloth and came into English from the French word "drap," meaning a piece of cloth. Think of the word "drape," it has the same roots. Clearly they're two entirely unconnected words,except that they share the misfortune of being constructed of the same phonemes. There's nothing wrong with a drab color, I often wear clothing of drab colors, preferring them to colors bold and attention grabbing.
But just for fun, for a moment, take a liberty with the language, and let them be connected in your mind. As a stay at home mom I often have nothing of interest to chat about on the phone with family. My days seem boring, and sometimes I am bored living out my day from morning til night. (I know, too, plenty of working women could say a lot about how dull the job is day after day after day.) I listen to the lies that any woman can run a vacuum cleaner, as if that is what my life is all about. I wonder if my husband might find a career woman fascinating, full of goals and ambition and a lot to talk about. I ask him, and he faithfully reassures me that's not the case. I know I'm not alone in this. I know other women, thoroughly convicted that they've chosen important work, family work, feel the same way, and it affects our feeling of worth. We know the objective truth about the value of children and the importance of loving your husband, but to let that truth genuinely direct our feelings is a difficult task. Our life feels drab, an undyed life, lacking in color or beauty.
A faithful wife is not drab, or a drab, to bring in the earlier meaning of the word. Proverbs tells us an excellent, noble wife is worth far more than rubies. An excellent wife is a jewel her husband will proudly admire and display as his greatest treasure. Our life as a wife and mother is rich in color and beauty, with facets that reflect back the light of the Savior. The noble in scripture wore cloth of Tyrian purple. The family of the Proverbs 31 woman wore cloth of scarlet. The wedding garments of Christ's bride are of a brilliant white. Christ's calling is not to an undyed life and a drab existence, but to something much more, a life of richness beyond measure.