Pygame surface transparency does not work

Ive had a problem with surface transparency in pygame, and its making me frustrated. I tried to find solutions from other posts, other sites, but to no avail. The problem is that when i try to make the surface transparent or translucent, it only returns the same surface but darker, even though i put SRCALPHA in the arguments.

Code:

import pygame
from pygame import Color

class Box:
    def __init__(self,
                 surface:pygame.Surface,
                 pos:tuple[int, int],
                 size:tuple[int, int],
                 borderwidth:int,
                 bg: tuple[int, int, int] | Color | str,
                 bc: tuple[int, int, int] | Color | str):

        self.surface = surface

        self.abspos = tuple([x+y for x, y in zip(self.surface.get_rect().topleft, pos)])

        self.bw = borderwidth
        self.body = pygame.Surface(size, pygame.SRCALPHA, 32)
        self.border_body = pygame.Surface([x+self.bw for x in size], pygame.SRCALPHA, 32)

        self.rect = pygame.Rect(pos, size)

        self.bg = bg
        self.bc = bc

    def _draw(self):
        self.body.fill(self.bg)
        self.border_body.fill(self.bc)

    def _place(self):
        self.surface.blit(self.border_body, [x-self.bw//2 for x in self.rect.topleft])
        self.surface.blit(self.body, self.rect.topleft)

    def place(self):
        self._draw()
        self._place()