While I was in the Pentacostal religion, I was told that women should always wear dresses, and that they shouldn't wear make-up
Again its that blanket word "Pentecostal" everyone who is Pentecostal must be the same as the church you knew.
Have you asked the women at work if they have to wear a dress, maybe they don't like wearing trousers or jeans.
I know many women who work in my place and do physical labour and wear dresses and they are not Pentecostals. How many housewives clean, cook and work around the house wearing a dress? Are they all Pentecostals? I remember my sister decorating a room wearing a skirt.
I have never heard of a Pentecostal church say women should only wear dresses and no makeup.
Plenty in my Pentecostal church come in slacks, Jeans and wearing make up.
It wouldn't matter what "religion" you looked at you will find some churches will have such petty little rules. Usually made up my their own local elders or pastor.
I know of churches, not Pentecostal either or JW, were the men must wear only white shirts and suits for church. They would have a fit if they came to mine, men dress in anything from suits to soccer kit.
I read on this forum how JW brothers had to wear white shirts only. Yet in my 20+ years as one I never wore a white shirt for a meeting or giving a talk. JW women had to wear a skirt/dress for meetings or on the ministry. But I knew plenty who wore jeans at home or slacks to work.
Again I have discovered it came down to how the Elders in different congregations viewed things and made their own petty little rules. Mainly to stamp their own authority on a congregation.