INTEGRITIAges 1-15 Kids Plain Blank T-Shirt Tee Shirt 100% Cotton Boys Girls Childrens Softspun Unisex School Uniform P.E. Gym

My son is 6 years old and need a brown top for his school play. Are the sizes true to fit. Unsure whether to get 5-6 or 7-8. He normally wears 6-7

Are these fruit of the loom?

Are the white ones the same as picture or Fruit of the loom?