First Opinion
Not very, some places its a gang sign and you could be shot at.
Another Opinion
As long as there are lace shoes and creative human beings, someone will always attempt to make an artistic or individual "statement" with laces, bows, or added garnishments such as fake gemstones, buttons, beads, etc. Long gone are the plain white "tennies" with plain white shoe laces of the 1940s to 1960s.
Whether having "artistic feet" is cool or overkill in fashion depends on what generation is decorating their feet/shoes. In the 1970s, it was a pretty new fad to use two colors; or to double the shoe laces, preferably ones with colors; or to add beads, etc. Then came "high tops" in the 1980s and wrapping laces around the ankle, using extra long laces. Then, the sport or running shoe type of tennis shoes were manufactured and having new Nike shoes meant being "cool" rather than how the shoes were decorated.
Whether different laces is a cool statement now I cannot say. But if you feel a need to experiment and decorate your shoes/feet, why not? (Just ask your parents for permission first if the decoration you want will alter new or expensive shoes.) Even if other people aren't changing their laces, it's okay to be the first in your class to do it.
Because it looks cool and it personalizes it to each outfit depending!
The boots cost 40.50, the laces 0.50 - QED
Each wire carries a different voltage.
Each colored complex has a different maximum of absorption.
You split the stem in half and put each side in different colored water.
Because you get different colored cells from each parent
Tajiri Tajiri
you have a problem but still kinda cool :)
Because there are different types/species of dolphins and each one looks the same.
Colored rubber bands may be useful while organizing different papers or objects. For example: when studying for a science exam, you may organize cue cards into different categories (biology, chemistry, anatomy, etc.) and use a different colored rubber band to secure each section of cue cards.
I think it might be different colored t-shirts to represent the different colors for each team. This would mean that they have to join a different team to the one they're in at the moment!
it depends on the plant, each plant reacts in a different way.