LED Switchbacks for My Turning Signals? Help!

Okay so I have some aftermarket halo projector head lights from eBay and I wanted to do a mod...

I wanted to take out the orange/amber bulbs from the turning signals and the small little parking light and replace them with white LED's. Thing is, I need turn signals, and I can't just use white signals as that's illegal, so I have seen people do switchbacks where the light is white when not turning and when you put the turning signal on it switches to the amber color like on Audi's and such. I have my LED halos and that light strip underneath hooked up to the parking lights just FYI. So how can I manage to do this, and what do I need to do this? (like what things do I need to buy and such)

Please help! Thanks.

Here is a pic of my truck.