Unless your Basketball team has rules and regulations against gray colored clothing, then yes, you surely can practice in a gray shirt during basketball. There is no reason not to.
gray under sleves and a white polo shirt
a black shirt with a gray design
Look on the internet for basic basketball drills to practice and PRACTICE, PRACTICE, AND PRACTICE
1/6. There are 6 possible combinations of 2 you could pull out of the washer (red&black, red&white, red&gray, black&white, black&gray, white&gray), and red and black is one of them.
You can wear a gray shirt with brown pants, but you might want a real light gray or try a green shirt with brown pants might be better.
your school uniform or if its just for practice. spandex or basketball shorts and a loose shirt, and also throwing shoes if you have them.
Practice! Practice! Practice!
a grey shirt or a gray pants.
Yes, for years a gray suit with a blue shirt have been the standard in business attire. This has evolved to any combination of gray pants and blue shirt, blue pants and gray shirt, etc. This is one of the most popular color combinations in the American society.
14 IS ON HIS BASKET BALL SHIRT
* PRACTICE * PRACTICE * PRACTICE
Practice, practice and practice.