I'm creating a custom basemap for my organization. I started with the Light Gray Canvas base because I want my custom basemap to be fairly simple. I've edited all the colors and have it looking pretty much the way I want it, except for the highway shields. The Light Gray Canvas basemap uses rectangles for all highway shields which I've always thought was a strange choice. I want to use the more common highway shields like most of the other basemaps use.
I have downloaded the shields used in the Streets basemap and then added them to my custom basemap. The problem I am running into is that every road in the Light Gray Canvas basemap uses the same shield. So if I change the rectangle to an interstate highway shield, every shield on my map becomes an interstate highway shield even if it's a US or state highway. I think I need to somehow classify the roads in order to be able to assign the right type of shield to each road but I don't know the best way of going about this.
Can I copy and paste the relevant section of JSON code from the Streets basemap into my custom basemap? If so, which sections should I use? Or would it be easier to start over using a different basemap that has the shields I want? I spent a full day creating my custom basemap so I'd rather not start over if possible.