They are reading very grey. If it was me, I'd be messaging the person who made them to see if they have any fabric scraps they could send me for dye sampling......or where they got the fabric so I could buy some myself. You will also need to know the content if its poly....if its more then 35% you will need to stove dye with dyemore.
If its mostly cotton/natural fabric.......I'd be looking at sampling with riit dye as its easier to tinker with the recipes. I cut the tops off 4 pints of milk and use those to sample.....I used the recipe for 'socks' with 1 liter of water with a tiny bit of fabric.
I'd start with some thing like this one below... then depending on how it comes out, either tinker with it.....or if its not right trying maybe Spanish olive or olive branch. I usually line up my milk bottles and label them, as I try a few recipes at one time.
https://www.ritdye.com/color-formulas/t ... &pantone=0