If your Trillium has the original fixtures you should have the standard "1156" bulb base. You can check by pulling the bulb out and visiting an auto parts store, finding their 1156 bulbs and comparing your bulb to the one on their shelves. The glass part of the bulb may look slightly different and the metals they use in the base -- a brass colored metal or shiny nickle -- may differ, but otherwise the size,shape and the way the bottom of the bulbs should look like the same thing.
If they are different, I'd get this LED panel from V-Leds
because it comes with an assortment of different bulb bases, so it should fit no matter what you have in your trailer. These are the LED panels I use in our trailer and I like them a lot, but if your trailer ficxtures take 1156 bulbs the SuperBrightLEDs panel should work fine as well.`