I think I would explain colors to a blind person by explaining the feeling. = I think I would explain colors to a blind person by describing the feelings they evoke.
 “explaining the feeling” → “describing the feelings they evoke” is more natural and clear.

For the blind, they don't have experiences about see the colors, I would explain the emotion related to colors.
 = Blind people do not have experience seeing colors, so I would explain the emotions associated with each color.
 “they don't have experiences about see the colors” → “do not have experience seeing colors”; “the emotion related to colors” → “emotions associated with each color.”

For example, red is connected to the passion and yellow is related to the warmth. = For example, red is associated with passion, and yellow is associated with warmth.
“connected to the passion” → “associated with passion”; “the warmth” → “warmth” (no article).

These emotions help them to understand the colors. = These emotions can help them understand colors.
“help them to understand” → “help them understand” is simpler and natural; “the colors” → “colors.”

ESSAY FEEDBACK:
Your essay presents a clear opinion that online learning cannot fully replace in-person education, and you provide relevant reasons to support your argument, which is good. The logic of your points is understandable, but the arrangement could be smoother: for example, you could first explain the issue with academic performance, then discuss communication and interaction, and finally provide examples or evidence. Some sentences need grammatical corrections and more precise word choices to improve accuracy and coherence, for instance, “they lack of communication skills” should be “they lack communication skills,” and “in some point” should be “to some extent.” Overall, your ideas are relevant and coherent but linking your points with transition words and refining sentence structure would make the essay stronger and easier to follow. KEEP UP THE GREAT WORK!