The Pokemon will have an alternate coloring just like in the video games. You could use a chart of shiny Pokemon compared to regular ones to decide. I know that you said besides looking at it but that's not really hard. Some of them will have a star after their name but others will not so you will pretty much just have to look at it if I am not mistaken.
As you can see here there are no stars on this shiny Duskull (Stormfront SH2).
Here is a list of shiny cards.
