The label of the read callback is not clear enough

It is gray when unread, and blue when the other party has read the message, but it is difficult for people with mild color blindness to distinguish.
It is recommended not to display √√ when unread, and display √√ after the message has been read. Or use other labels, such as:
A: Unread √, Read √√
B: Unread ○, Read √√
And so on...