Light is a powerful tool to probe the structure and dynamics of biomolecules. In most cases, this cannot be done directly with visible light because of the absence of absorption by those biomolecules. This problem can be overcome by incorporating organic molecules (chromophores) that show an optical response in the vicinity of those biomolecules. Since those optical properties are strongly dependent on the chromophore's environment, time-resolved spectroscopic studies can provide a wealth of information on biosystems at the molecular scale in a non-destructive way. In this work, we give an overview on the multiscale computational strategy developed by us in the last 8 years and prove that theoretical studies and simulations are needed to explain, guide and predict observations in fluorescence experiments. As we challenge the accepted views on existing probes, we discover unexplored abilities that can discriminate surrounding lipid bilayers and their temperature- as well as solvent-dependent properties. We focus on one archetypal chromophore: Laurdan. Our method shows that conformational changes should not be neglected, as the probe behaves as solvatochromic probe in DOPC but as molecular rotor in DPPC. As a result, we prove that they exhibit different properties in different lipid membrane phases. We see that the two conformers are only blocked in one phase but not in another. Moreover, we observe a strong effect of the temperature on the ability of Laurdan to behave as either molecular rotor or solvatochromic probe.