“My eyes are gray, but they absorb the colors blue or violet easily from surfaces around them.” – TVL

His first study of his own reflection after being turned: “and my eyes had been transformed from their usual blue to a mingling of violet and cobalt that was softly iridescent.” – TVL

[fanart by theivorywolf]

Magnus, in TVL: “…and the blue sky fixed forever in your eyes.” Magnus, TVL

So Lestat’s eyes:

• had this effect as a mortal and looked blue to Magnus; or
• were actually blue as a mortal and not gray-blue-violet-magical until he was turned; or
• really were always closer to gray-blue than just gray.

This is if we trust Magnus, do we really? IIRC, it’s the only description we have of mortal!Lestat’s eye color. IDK! Lestat supposedly shares his mother’s features

and coloring

(”In fact I resemble her at least superficially.” –TVL) and she is described as having blue eyes:

Lestat, in TVL about mortal!Gabrielle: “And she had very clear cobalt blue eyes fringed with thick ashen lashes.”

Khayman, in QOTD: “There wasn’t a particle of fear in her cold blue eyes…”

Lestat, in TVL about vampire!Gabrielle:
“Her eyes opened. Violet blue and glittering,”

Marius, in QOTD:  “The ice-blue eyes, darkening with laughter…”

Khayman, in QOTD: “… [Lestat’s] violet blue eyes.”

Jesse, in QOTD: “[Lestat’s] pale crystalline blue eyes…”

Akasha, in QOTD:  “to see the light in your blue  eyes,”