The beer style Trappist changes black color to quoit after the first fermentatio

My beer I am used trapensis before the first fermentation it was of a black color foreseen in the standard. After the first fermentation the beer has acquired a brown clear color. Might someone explain the reason to me? Thank you.

Mi cerveza estilo trapensis antes de la primera fermentación era de un color negro previsto en el standard. Tras la primera fermentación la cerveza ha adquirido un color marron claro. Alguien me podría explicar a que puede ser debido este cambio de color? Gracias

Beer that hasn't been clarified will have a lot of solids floating around in it, especially after you pitch your yeast.  In my experience, everything looks darker in the primary and gets lighter and brighter after flocculation and settling.  Even the darkest of the Belgian styles should have ruby highlights and not be cold black like an Irish stout.