Test day.
2 hours prior to test I get up and urinate then drink:
1 quart of liquid, creatine supp. 3 aspirin, 4 rolaids
1hour prior
1 quart of liquid, 3 aspirin, b vitamin, 4 rolaids
1/2 hour prior
2 quarts liquid, 2 aspirin, 4 rolaids
I uriniate as I feel the need throughout the process and right up to test time, there is no worry about being able to produce a sample, trust me your problem is going to be getting there without going in the car!
I suggest that you test the process with water vitamin alone sometime prior to test day to determine at what point it is best to take the aspirin. Take it too late and it doesnt have time to show up. Take it too early and it flushes out before your test.
Color is probably the least thing to worry about though givin thatmost people that drink a healthy amount of water have pretty clear urine.
Well that's it. That has worked for me three times now.
I am also a proponent of using home tests and doing dry runs to gain confidence that I am timing thing correctly and that it will work--nothing like that negative home test to eliminate some of the jitters.
http://www.marijuana.com/community/threads/dilution-and-aspirin-the-technique.152308/