Well as cool as purple would look, be aware that any light that isn't white or amber will definitely get you some attention from the police so just be careful. The purple lights you have probably seen driving around are just high color temperature HID bulbs. Like 8-10K. If you start looking at HID kits you will see "temperature" or "color" choices listed in K, which stands for Kelvin.
If you want to replace the DRL with different bulbs there are two ways to go. Halogens will allow you to keep your high beam functionality and run as DRLs. If you get LED bulbs you will have a great looking DRL but will definitely lose some of the high beam. A lot of LEDs can't throw nearly the light a regular style bulb can. They do look very crisp and sharp in the housing but output is comparatively terrible. That said.... it's really up to you on how much you use or think you will need your highbeams.
I would recommend a bright white bulb just for safety/legality and a halogen for the use of the high beam. Nokya bulbs are pretty reliable and available as are Putco. I can't think of any others off the top of my head.
I do think a nice LED bulb in there just to be a DRL will look the best though. It will be very crisp and your car will stand out. Just depends on what you really need or want. If you really really really really want purple.... try and find a purple LED bulb. Probably your best bet for actually getting the color you want.
SEDAN and COUPE have different bulb sizes in certain areas so be sure to get the ones you need.
2012 SEDAN High beam bulb is a 9005. You can get them in LED or halogen.
I really like my blue LED's that I got from ijdmtoy. Although you have to remember you will get an error message in iMid if you don't have a proper drl resistor.
I'm gonna take mine out soon to get 2500k yellow halogen bulbs. Losing the high beam functionally is something I don't want to live without in winter when it gets dark really fast.