Trying to improve the condition, I bought Azoo coral blue light to replace
my existing bulbs, ordinary shoplight Philips TLD. My idea, if the light
works well with coral then it should be worked even better with plants.

Why would the situation need improving if your plants are healthy?

Am I making a big and silly mistake by changing the bulb ? But the blue
light give more pleasant looking.

Try using full spectrum (daylight) bulbs for a pleasing, natural and healthy
alternative to your old shop lights.

N. Wise