Indeed this young seedling is still green and has turned bluish under the influence of the first fluorescent lamp that I have from the front of tank (it is not Led, only a T5 fluorescent lamp). The first pictures in previous posts shown a bluish mature, mother plant in normal lighting. I do not use light to artificially coloration plants for photos. Just such fluorescent lamp is recommended for better plant growth.
In my other aquariums, the first lamps has white light.