The lake changes its color based on how the sun shines on it.
It is a delight to your eyes and pure like a morning due, the stillness, the calmness & the beauty is so overwhelming that it will leave you mesmerized.
You can visit Chandratal during your road trip to Spiti or Ladakh Or Short Road Trip for Chandratal alone Or Combine Lahaul Valley & Chandratal
You will get these color of the lake only in the afternoon the sun which is bright and full. If it is cloudy or if you go in the evening or early morning when the sun is slanting on it, then the color will be different. Besides, the stillness is dependent on the wind. There has to be no wind. If there is wind, you will see ripples on the lake.
It is the principle for all lakes in the himalayas, whether it is Pangong Lake or Tso moriri or Suraj Tal or any other lake.