I wouldn't hesitate to have him tested, provided it is done by persons who are well-trained and who know how to avoid making it stressful for the child—and for you. If he is already recognizing words, shapes, and colors and is only in kindergarten, he can't be too far behind. A good assessment procedure will help identify strengths as well as weaknesses and should provide you with helpful clues as to how you can facilitate his progress. On the other hand, an evaluation that is concerned only with labeling and classifying is no help to anyone—your son, his teacher, or you. Find out about the procedure before you consent or refuse.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.