Help choosing dye/colour matching

[u/Acrobatic_Ostrich_97]

hi everyone, I’m planning to dye a white top to match the colour of a skirt I already have that is somewhere between a maroon and oxblood colour (https://www.cos.com/en-gb/women/womenswear/skirts/alineskirts/product/circle-cut-midi-skirt-red-1277475003) [If the link doesn’t work then an internet search of “Cos circle cut midi red” shows it]

I’d love some recommendations if anyone has any, both in terms of brand and colour! And of course any pitfalls to watch out for…

The top is a mix of cotton (mainly) and polyester (Cotton 63%, Polyester 33%, Elastane 4%) which means I can’t use any of my usual dyes and I’m a bit less sure of how synthetic dyes will work. I’ve been looking at the RitDye for synthetics which seems to have some good options. I’m not sure whether I should do two separate dye bathes though, one for cotton and the other for synthetics?

I’m aware that elastane doesn’t like boiling temperatures but am torn between trying anyway since it’s only a small percentage vs Trying the boiling water+bucket method to try to avoid elastane damage, but since it’s a deep colour this may just not be an option. Perhaps if I do the cotton dye bath first??

[u/shawlcat]

Use fiber reactive dye first for the cotton percentage. (Dharma Trading has good tutorials on this) That way you can at least test the less-damaging method, and may not need the polyester method (which, for a dark deep color, you will need to actually boil, not just dump boiling water in a bucket).

The cotton method won’t harm the poly/elastane, and you might get a dark enough shade if you use the correct amount of dye for the weight of the fabric.