Is it permissible for me not to make up the prayer if I doubted what I saw after seeing the white discharge, whether it was a yellowish discharge or normal wetness, and I considered it a yellowish discharge, based on the principle of choosing what is easier for me?

You must inquire about the ruling of Allah; do not follow the concessions of scholars. And the statement that one who doubts between mani (spermatic fluid) and madhi (pre-seminal fluid) has a choice is correct. If you see the white discharge followed by a yellowish discharge, it is not considered menstruation unless it occurs within the period of your regular cycle. If you doubt whether what you saw was yellowish or not, the default is the continuation of purity, and you must make up the prayers you missed. The view that making up prayers is obligatory is the opinion of the majority and is more cautious, while the view that it is not obligatory is also a valid opinion.