Enables colors in the Windows terminal for Java console programs. Read the comment before blindly copy pasting!

Main.java

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.net.URL;
import java.net.URLClassLoader;

public class Main {
    static void enableColor() {
        // https://stackoverflow.com/questions/52767585/how-can-you-use-vt100-escape-codes-in-java-on-windows
        try {
            // Load classes
            URLClassLoader loader = new URLClassLoader(new URL[] {
                    new URL("https://repo1.maven.org/maven2/net/java/dev/jna/jna/5.11.0/jna-5.11.0.jar"),
                    new URL("https://repo1.maven.org/maven2/net/java/dev/jna/jna-platform/5.11.0/jna-platform-5.11.0.jar")});
            Class<?> Function = loader.loadClass("com.sun.jna.Function");
            Class<?> WinDef = loader.loadClass("com.sun.jna.platform.win32.WinDef");
            Class<?> WinNT = loader.loadClass("com.sun.jna.platform.win32.WinNT");
            Class<?> HANDLE = null;
            Class<?> DWORD = null;
            Class<?> BOOL = null;
            Class<?> DWORDByReference = null;
            for (Class<?> c : WinDef.getClasses()) {
                if (c.getSimpleName().equals("BOOL")) BOOL = c;
                else if (c.getSimpleName().equals("DWORD")) DWORD = c;
                else if (c.getSimpleName().equals("DWORDByReference")) DWORDByReference = c;
            }
            for (Class<?> c : WinNT.getClasses()) {
                if (c.getSimpleName().equals("HANDLE")) HANDLE = c;
            }

            Object GetStdHandleFunc = Function.getDeclaredMethod("getFunction", String.class, String.class).invoke(null, "kernel32", "GetStdHandle");
            Object STD_OUTPUT_HANDLE = DWORD.getConstructor(long.class).newInstance(-11);
            Object hOut = Function.getMethod("invoke", Class.class, Object[].class).invoke(GetStdHandleFunc, HANDLE, new Object[] {STD_OUTPUT_HANDLE});

            Object p_dwMode = DWORDByReference.getConstructor(DWORD).newInstance(DWORD.getConstructor(long.class).newInstance(0));
            Object GetConsoleModeFunc = Function.getDeclaredMethod("getFunction", String.class, String.class).invoke(null, "kernel32", "GetConsoleMode");
            Function.getMethod("invoke", Class.class, Object[].class).invoke(GetConsoleModeFunc, BOOL, new Object[] {hOut, p_dwMode});

            int ENABLE_VIRTUAL_TERMINAL_PROCESSING = 4;
            Object dwMode = DWORDByReference.getMethod("getValue").invoke(p_dwMode);
            DWORD.getMethod("setValue", long.class).invoke(dwMode, (int) DWORD.getMethod("intValue").invoke(dwMode) | ENABLE_VIRTUAL_TERMINAL_PROCESSING);
            Object SetConsoleModeFunc = Function.getDeclaredMethod("getFunction", String.class, String.class).invoke(null, "kernel32", "SetConsoleMode");
            Function.getMethod("invoke", Class.class, Object[].class).invoke(SetConsoleModeFunc, BOOL, new Object[] {hOut, dwMode});

            loader.close();
        } catch (IOException | ClassNotFoundException | IllegalAccessException | IllegalArgumentException | InvocationTargetException | NoSuchMethodException | SecurityException | InstantiationException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        enableColor();
        final String ANSI_RED = "\u001B[31m";
        System.out.println("Demo: " + ANSI_RED + "red");
    }
}

To use: simply add the call to enableColor() anywhere before the first print statement with color. Typically, right at the start of main will work.

Demo (with color enabled):

Demo (without enabling color):