modify the color a string of characters in python 3.6

[atlass218]

I try the procedure of the previous link cited, but I have a problem :

this is the end of the code of the update fonction of the Text widget tkinter:

T_cev_loc35R.insert(END,contenu_table_cev_loc35R)
        if variable_case_correction_loc35R.get ()==0 :
			
            T_cev_loc35R.tag_add("start", "3.5", "3.53")
            T_cev_loc35R.tag_config("start", foreground="black")
        else :
			
            T_cev_loc35R.tag_add("start", "3.9", "3.49")
            T_cev_loc35R.tag_config("start",  foreground="green")
   
curseur3_cev_loc35R.close()

the coloring of the character string is relative to the indexing of the line
when I introduce another data into my database
the line 3 is changed and is not colored at green because of the condition about "variable_case_correction_loc35R"