I do not think that is possible. Coumarin derivatives has absorption peak in the range of 350-450 nm. Anthracene absorbs at 350 nm whereas malachite green absorbs at 600 nm (both have three benzene ring). More importantly, the spectra shape and position, especially the emission, is strongly dependent on the solvent. But  for a particular class of molecule, from the presence of functional group (nature of polarity), an estimation  of spectral profile can be made. It is not  clear to me what do you mean by the "shape of the aromatic moeity".

I do not know such software. As Tuhin Khan said in a previous answer, absorption and especially emission spectra depend strongly on the environmnent (pH, hydrophobicity or hydratation, stacking, position in DNA or RNA grooves, etc.), and changes of the spectra could be drastic (see, for example, articles by Alain Burger from Nice University, France). Even similarity of the structures does not give a clear answer.

I agree fully with the answer posted from Tuhin and Alexandre.

concerning the "shape of the aromatic moiety", please read the interesting book of Erich Clar in English language. My source is in German language/(Springer Verlag 1941) (see my jpg file 1). this aspect is an old theory.

Concerning the estimation of absorbance or fluorescence, there are a lot of books and  papers  in various languages (see file 2/booklet F. Doerr(1962) German language)..

According to the answers of Tuhin and Alexandre, a cheap software for the prediction of shape according to the various conditions (p.e solvent, properties of the dyes (acid or basic) , monomer or dimer or highly aggregates ...) doesn 't exist at this time.

JRG

Please read this link :

http://www.chem.gla.ac.uk/staff/alanc/clar.htm

and try to obtain this book of Erich Clar

https://www.amazon.com/Polycyclic-Hydrocarbons-Erich-Julius-Clar/dp/B0007I9ZXS

in English language.

JRG

To estimate fluorescence and absorption profiles we have to take in attention two factors. 1) Atomic structure of molecule and 2) fluctuation of her intermolecular interections whith solvent. Second factor is considered in detail in my two works:

https://www.researchgate.net/publication/264392048_Gas-phase_energy_of_the_S-2_-_S-0_transition_and_electrostatic_properties_of_the_S-2_state_of_carotenoid_peridinin_via_a_solvatochromic_shift_and_orientation_broadening_of_the_absorption_spectrum?_iepl%5BviewId%5D=Yt47cEWTWS79XQdak0uW3brmG0mOMCBSjWhc&_iepl%5Bcontexts%5D%5B0%5D=prfhpi&_iepl%5Bdata%5D%5BstandardItemCount%5D=5&_iepl%5Bdata%5D%5BuserSelectedItemCount%5D=5&_iepl%5Bdata%5D%5BtopHighlightCount%5D=1&_iepl%5Bdata%5D%5BstandardItemIndex%5D=4&_iepl%5Bdata%5D%5BstandardItem4of5%5D=1&_iepl%5BtargetEntityId%5D=PB%3A264392048&_iepl%5BinteractionType%5D=publicationTitle

https://www.researchgate.net/publication/233395978_Solvatochromism_and_Nonradiative_Decay_of_Intramolecular_Charge-Transfer_Excited_States_Bands-of-Energy_Model_Thermodynamics_and_Self-Organization?_iepl%5BviewId%5D=5OZHZqAr5jG8bDeqNLfjgLG7&_iepl%5BprofilePublicationItemVariant%5D=default&_iepl%5Bcontexts%5D%5B0%5D=prfpi&_iepl%5BtargetEntityId%5D=PB%3A233395978&_iepl%5BinteractionType%5D=publicationTitle

and in book:

https://www.researchgate.net/publication/301803599_Photoprocesses_in_biomolecules_carbon_nanoparticles_and_polymer_solar_cells?_iepl%5BviewId%5D=5OZHZqAr5jG8bDeqNLfjgLG7&_iepl%5BprofilePublicationItemVariant%5D=default&_iepl%5Bcontexts%5D%5B0%5D=prfpi&_iepl%5BtargetEntityId%5D=PB%3A301803599&_iepl%5BinteractionType%5D=publicationTitle

Herein you’ll found as to calculate the inhomogeneous broadening of spectra.

Article Gas-phase energy of the S-2

In general, any quantum-chemical program that is able to find the geometry of the ground and excited states is suitable for getting spectra in vacuum.

You can use HypeChem.

For absorption spectrum:

Setup: semi-empirical – PM3.

Options: RHF, Lowest state.

Command: Compute – Geometry Optimization. (Wait until the calculations are complete.)

Command: Electronic Spectrum.

For luminescence:

Setup: semi-empirical – PM3.

Options: RHF, Next Lowest state.

Command: Compute – Geometry Optimization. Processing… Save result.

Setup: semi-empirical – PM3.

Options: RHF, Lowest state.

Command: Compute – Single Point CI...

Command: Electronic Spectrum.

 But You must be remember that program of quantum-chemical calculations is instrument and is not a gospel truth.