ggiSetGCForeground, ggiGetGCForeground, ggiSetGCBackground,
ggiGetGCBackground : Set or get the foreground or background
color used in drawing operations in a visual

#include <ggi/ggi.h>

int ggiSetGCForeground(ggi_visual_t vis,ggi_pixel  color);

int ggiGetGCForeground(ggi_visual_t vis,ggi_pixel *color);

int ggiSetGCBackground(ggi_visual_t vis,ggi_pixel  color);

int ggiGetGCBackground(ggi_visual_t vis,ggi_pixel *color);

ggiSetGCForeground and ggiGetGCForeground set or reads the
current colors for the foreground, used in all normal
drawing functions.

ggiSetGCBackground and ggiGetGCBackground set or reads the
current colors for the background, used in two‐color
operations like drawing text.

All four functions 0 for OK.