Wow, a blue dash in an SS, I had to think about that for a minute.
On the underside of the trunk lid is the SPID, it's a decal with all the options on the car, kinda build sheet. I'm thinking that code should be on the SPID. Others may know what that color is.
A while ago I bought a pint of SEM interior paint using the gray code for my 86 at my local body/paint supply store. They had the mix formula on file and by using the SEM was able to make the correct sheen. https://www.semproducts.com/
As far as spraying the SEM a Prevail sprayer worked very well. Have used a Prevail to spray many other jobs, you just need to know it's restrictions. https://preval.com/