Colors and Palette

Colors & Palette in graphics.h

Use color functions to control line color, background color, fill color, and palette entries. This page covers the practical differences between setcolor(), setbkcolor(), and palette APIs.

Core Color Functions

void setcolor(int color);
void setbkcolor(int color);
int getcolor(void);
int getbkcolor(void);

setcolor(): Sets current drawing color (lines, outlines, text).
setbkcolor(): Sets graphics background color.
setfillstyle(pattern, color): Sets fill color separately from outline color.

Common Color Constants

Constant	Typical Meaning
`BLACK`	0, usually background default
`WHITE`	15, high-contrast line/text
`RED`, `GREEN`, `BLUE`	Primary drawing colors
`LIGHTRED`, `LIGHTGREEN`, `LIGHTBLUE`	Brighter variants
`YELLOW`, `CYAN`, `MAGENTA`	Useful highlights

Exact output depends on driver/mode. Keep color choices high-contrast for portability.

16 Available Colors (0-15)

This demo draws all 16 standard graphics.h colors with their index and constant name.

#include <graphics.h>
#include <conio.h>
#include <stdio.h>

int main() {
    int gd = DETECT, gm;
    int i, x, y;
    const char *names[16] = {
        "BLACK", "BLUE", "GREEN", "CYAN",
        "RED", "MAGENTA", "BROWN", "LIGHTGRAY",
        "DARKGRAY", "LIGHTBLUE", "LIGHTGREEN", "LIGHTCYAN",
        "LIGHTRED", "LIGHTMAGENTA", "YELLOW", "WHITE"
    };

    initgraph(&gd, &gm, "");
    setbkcolor(BLACK);
    cleardevice();

    setcolor(WHITE);
    outtextxy(20, 10, "graphics.h 16-color palette (0-15)");

    for (i = 0; i < 16; i++) {
        x = 20 + (i % 4) * 150;
        y = 40 + (i / 4) * 95;

        setfillstyle(SOLID_FILL, i);
        bar(x, y, x + 54, y + 42);

        setcolor(WHITE);
        rectangle(x, y, x + 54, y + 42);

        char label[64];
        sprintf(label, "%2d: %s", i, names[i]);
        outtextxy(x + 62, y + 15, label);
    }

    getch();
    closegraph();
    return 0;
}

Run this to view all 16 colors at once.

Palette APIs

void setpalette(int colornum, int color);
void setallpalette(struct palettetype *palette);
void getpalette(struct palettetype *palette);

Palette functions remap color indexes. They are mode-dependent and may not behave the same in every environment.

Example Program

#include <graphics.h>
#include <conio.h>

int main() {
    int gd = DETECT, gm;
    initgraph(&gd, &gm, "");

    setbkcolor(BLACK);
    cleardevice();

    setcolor(WHITE);
    rectangle(60, 60, 280, 220);

    setfillstyle(SOLID_FILL, LIGHTBLUE);
    bar(80, 80, 260, 200);

    setcolor(YELLOW);
    outtextxy(90, 230, "Outline and fill can use different colors");

    getch();
    closegraph();
    return 0;
}

Click Run (DOS) to test this quickly.

Common Mistakes

Assuming setcolor() changes fill color automatically.
Using low contrast between foreground and background.
Relying heavily on palette remapping in incompatible modes.

Next: Fill Styles & Patterns to control shading behavior with setfillstyle() and setfillpattern().