Sister, applying nail paints doesn’t let water go trough the nails and thus it doesn’t let the wudu be finished properly. In case of Qur’an, yeah u can touch the Holy Qur’an if you’re neat and clean( i mean with nail paint) but In case of Salah and other mandatory prayer, wudu is a must and with nail paint, your wudu won't be done at all! So,It's better to leave the habit.(I'm telling u for a good reason) Trust me,you're gonna fall in love with your bare nails In Sha Allah! May Allah help you!