Color color what color

Economically it works best to buy a pack of toothbrush rather than buying them individually. A pack of 12 normally comes with four repeating colors but we are a family of five; which means that at least two of us will end up using the same color.

We take care to mark them apart with our initials or tie a rubberband around it or something of that sort. But that is not always a foolproof method as the initials are erased off with use or the rubber bands get removed or exchanged that soon we lose track of whose is which.

This was never a problem before when kids had their favorite character toothbrush. Joshua's would be a Spider man or Bats man or Elmo. The girls would pick Barbie or Dora the Explorer or Winnie the Pooh. However now that they are bigger they have started using adult size regular medium bristle toothbrush which is the cause of this seemingly never ending chaos around the house.

To make matters worse I normally maintain three sets of toothbrush - one in all bath rooms - thinking it would be easy for the kids to grab hold of one that is closeby. Not only that, as one of ours gets worn out, we grab a new color from the lot which could be already rotating among the rest of the family members. This only makes it more confusing to decide which is whose. Saturday mornings the regular conversation goes like this: (as other days I hand them their toothbrush when they are in the shower)

Rachel: "Who used the red tooth brush?"
Sharon: "Why? I did; it's mine"
Rachel: "No; it is not. The red upstairs is yours; this is mine"
Sharon: "No! This is mine; ask Mommy"
Two in unison: "Mommy, whose is the red tooth brush downstairs?"
Mommy: "Downstairs? Red? That's Joshua's"
Three in unison: "Mommmmmmmyyyyyyy....!!!!"
Mommy: "Okay, let me go over the colors once again. The red one upstairs is Sharon's; the red downstairs is Joshua's. One in the basement without the rubberband is Rachel's and with is mine. But don't forget the red with three lines on it that almost looks new - that is Daddy's; he got it from the dentist last time and so it looks different from ours; okay? Is this now clear?"

Ask me to repeat it, I might get this mixed up myself. I have absolutely no idea how to resolve this problem once for all. Any ideas will help...