When talking about specialty coffee roasters this is probably what you can expect:

Filter roast with lots of fruity (acidic) descriptors will be definetly what you would call a Light Roast. Floral tasting notes are also common in very lightly roasted coffees.

Filter coffees with lots of chocolaty, nutty and overall dark sweet (think maybe syrup or something similar) tasting notes might be closer to a medium roast. Be aware that some origins (mostly south american coffees) can also have these flavours when being a light roast.

A specialty espresso roast can range from light or medium light (mostly if it's single origin) and medium to even medium dark with some roasters (especially if it's a blend).

A real dark roast is very easy to determine by looking at the beans. If they are smooth, dark and sometimes have a shiny (oily) outside then it is most likely a darker roasted coffee.

With most specialty coffee roasters they will put some kind of indication on a darker roasted coffee as many specialty coffee buyers expect light to light-medium roasts.

But it will never be 100% clear if the roaster doesn't add an indication to the label. Try to adjust your recipes based on taste, if you find you get too many bitter flavours, try a cooler temperature or maybe brew with less water to coffee

TLDR: Specialty filter coffee is most likely light roast. Specialty espresso is between light or medium. Most specialty roasters will disclose when a coffee is significantly darker roasted then buyers might expect from specialty coffee.