#30 is Shun Mark's color code, BTW. So, researching this, from SM's main company page we get this:

http://www.sl-thread.com/en/products/product_25.html showing T-70, T-90, T-135, T-210, T-270 as weight. And we know this is the right product, because the other one is poly core, not nylon.

So now, which weight do you have? Well, another company has the same usage, but they use D Tex system. (The 150 is weight, the 3 is strands wrapped together).

https://www.amazon.com/Upholstery-Outdoor-Drapery-Beading-Luggage/dp/B01C26BBI4?th=1In the Q&A they say it's T92...but now Shun Mark doesn't have that, but they do have T90, so you can assume that SM will be in the same range, which leaves you with the T90.

So now you have the Tex, find the needle.

https://www.tolindsewmach.com/thread-chart.htmlOn that you see a 19/120 for the T92, so you have a needle size. (18 or 20 is going to be the easier to find, though, but you now have a range of sizes.)

So, what are you sewing? Canvas? Outdoor furniture covers? Marine stuff? Well...

https://www.sailrite.com/Notions/Sewing-Needles/Sewing-Machine-NeedlesAnd that explains the different types and what you may need to choose from there to find the right needle.

In a tl; dr, researching shows it to likely be T90, needle size 18 or 20 based on fabric and a sharps for general purpose.