"Ayakkabının rengi ceketimin rengine benziyor."
Translation:The color of the shoe looks like the color of my coat.
The difference is that "rengi" is correct and "renki" is wrong :)
The Persian word is reng. Word-final consonants are usually devoiced in Turkish, so Arabic or Person words such as kitab, reng, wucud turn into kitap, renk, vücut in Turkish - but when you add a vowel to them, then the last letter changes (or you could say, the original sound surfaces again) and so "his book, its colour, his body" are kitabı, rengi, vücudu.