This is the part almost nobody explains, and it is the reason we will not sell you our coveralls as high-visibility workwear no matter what colour you order them in.
Fluorescent dyes cannot be fixed to 100% cotton at the chromaticity and luminance a hi-vis standard demands. Certified high-visibility background fabric is essentially always polyester or a polyester-rich blend, because that is what will hold the dye. This is a property of the fibre, not a choice we have made.
So our orange coverall is standard safety orange. It looks orange. It is not fluorescent, it does not glow in low light, and under the standards it contributes zero background area. Our navy, blue, grey, red and white contribute zero as well.
That is what settles it, and it is worth being precise about why. Our coveralls carry retroreflective tape on the shoulders, upper sleeves and lower legs. We have not had its total area measured against the class minima, so we make no claim either way about that half of the requirement. It does not matter. The two requirements are additive: EN ISO 20471 Class 1 also needs 0.14 m² of fluorescent background, and our background area is zero at every class. No quantity of tape closes that gap.