﴿ قَالُوا۟ ٱدْعُ لَنَا رَبَّكَ يُبَيِّن لَّنَا مَا لَوْنُهَا ۚ قَالَ إِنَّهُۥ يَقُولُ إِنَّهَا بَقَرَةٌۭ صَفْرَآءُ فَاقِعٌۭ لَّوْنُهَا تَسُرُّ ٱلنَّٰظِرِينَ ﴾

“Said they: "Pray on our behalf unto thy Sustainer that He make clear to us what her colour should be. "[Mopes] answered: "Behold; He says it is to be a yellow cow, bright of hue, pleasing to the beholder."”

Please check ayah 2:71 for complete tafsir.