1958 Apache temp brake lights question

[RostaRob]

Hello...hoping I can get a little Christmas present in the form of some info/help. I removed and sold the stepside bed for my truck (already have a Fleetside to replace it with...no wiring from brakes). I purchased two signal indicators from O'Riellys to bolt to the rear frame so I can drive it to and from a local weld shop. So my question is did I purchase the wrong signal/brake lights? The purchased lights have a red and a black wire while the wires coming to the back of the truck are brown, green and yellow. Assuming the black is the Ground I'm not sure how the other wires tie in to the remaining Red wire of the new lights. Make sense? I'll try to attach a photo of the wiring. Any help would be appreciated so I can take my truck out over the next few days without having to resort to hand signals....not that most people on the road would even recognize what they meant...haha....and it's freezing right now.