The right aquarium lighting
Our model for a perfect aquarium lighting is and remains the sun, because animals and plants have adapted to the sunlight in the course of evolution. Some exceptions are cave dwellers or nocturnal aquarium dwellers which are not dependent on lighting.
The accurate spectrum or the colour temperature don’t really matter to the fish either. It’s more our personal taste which leads us to favour a lighting type. For the plants this is an entirely different story: they use the spectral components of the sunlight to generate energy through photosynthesis. If the visible light we supply differs too much from this light composition they are used to, photosynthesis will come to a halt and the plant won’t be able to grow optimally. Therefore we should always aim for a sun-like spectrum.
There are fish species which don’t like to be in bright light. As you probably keep such fish species with others and have plants in your aquarium, adapting the light won’t help much. Instead it is important that these fish species are given places to retreat and hide in. Floating plants, roots, stones and plants provide a means of creating “dark” areas, even in a bright aquarium.
The right light for aquarium plants
Using a floodlight to light your aquarium would not only lead to huge electricity bills, your plants would grow badly too. Strong light intensity alone is not enough!
All plants (land and water) have evolved to adapt to the full spectrum of sunlight and they use the energy for photosynthesis, i.e. for their food production. For photosynthesis, the plant requires the whole spectral range of sunlight (visible in the rainbow or prism) for its source of energy, plus water and CO2 (carbon dioxide). From this it produces sugar (its food), and oxygen is released as a "waste product".