I'm not an color expert, I'm sorry if I interpreted something wrong. It's based on the idea what our favorite colors are telling about us and the meaning of colors in general.

Red:

the fiery man who was born between dusk and dawn and who has to protect his people, be their guiding light in the darkness of the deep sea

The colour red is one of the four original colours and stands for love and passion

Red - the colour of the body and of blood. In the monotheistic religions, the colour even stands for the creation of mankind. Furthermore, red is not just a warm colour - it glows! Powerful red evokes associations of blazing fire and embers, thus symbolising an inexhaustible reservoir of strength. The effect of red is prestigious, uncompromising and full of energy.

Blue:

the lonely sensible artist who just wants to be loved unconditionally

The colour of harmony and trust

In contrast to the earthly, present red, blue symbolises the unreal. It stands equally for the dream of freedom and infinite expanses, but also for introversion and withdrawal into oneself. Blue stands for gentleness - but in contrast to the present, serene green, blue is calm through distance. At the same time, blue also represents a clear level-headedness, objectivity, neutrality and clarity - this instils confidence and conveys a feeling of security.

Purple:

The fusion of the opposites red and blue

The mystical beauty of violet is multi-layered and full of tension. From the far-sighted balance of blue in combination with the power of red, violet also stands for strength. Violet also stands for supersensuality - the sensual red and the spiritual blue make it diffuse and light.

Another meaning of violet is transformation - by merging the opposites of red and blue, it represents coping with phases of upheaval in life, from which the personality emerges stronger. Violet is mysterious, a "united dual nature" of blue and red, as C. G. Jung put it. Jung characterises violet as a symbol of the spiritual body, the combination of blue, the spirit, and red, the body.

I think this says so much about Rafayel, the duality in his being, the both sides of his persona he struggles so hard to unite.

The both sides of his being, the strong but gentle Sea God and the sensible, insecure artist. The assassin who is calculating and caring.

His love and responsibility towards his people and the love and devotion towards his bride. Both things are so important to him but they are excluding each other because he has to eliminate one to protect the other...