ANSI Colors Generator from RGB/Hex value in different Languages

colors.java

import java.math.BigInteger;

/**
 * colorises your text using ANSI
 * 
 * @apiNote Most terminals would work with this, some terminals won't
 * 
 * @author cindrmon
 */
public class Colors {

	public static final String CLEAR = "\u001B[0m";

	/**
	 * 
	 * selects a color using rgb/hex and converts to ANSI code
	 * 
	 * @param r - Red value (in decimal)
	 * @param g - Green value (in decimal)
	 * @param b - Blue value (in decimal)
	 * @return escape string with set rgb value
	 */
	private static String selectColor(int r, int g, int b) {
		if (r <= 255 && g <= 255 && b <= 255 && r >= 0 && g >= 0 && b >= 0)
			return "\u001B[38;2;" + r + ";" + g + ";" + b + "m";
		else
			return "\u001B[38;2;255;255;255m";
	}

	/**
	 * 
	 * selects a color using rgb/hex and converts to ANSI code
	 * 
	 * @param hexValue - color in hex value (don't include the '#')
	 * @return escape string with set rgb value (defaults to white if invalid hex
	 *         value)
	 */
	private static String selectColor(String hexValue) {
		String rHex = "";
		String gHex = "";
		String bHex = "";
		if (hexValue.length() > 6 || !hexValue.matches("[0-9a-f]{6}$"))
			return "\u001B[38;2;255;255;255m";
		else {
			rHex = hexValue.substring(0, 2).toUpperCase();
			gHex = hexValue.substring(2, 4).toUpperCase();
			bHex = hexValue.substring(4, 6).toUpperCase();
		}
		// Convert to decimal
		BigInteger r = new BigInteger(rHex, 16);
		BigInteger g = new BigInteger(gHex, 16);
		BigInteger b = new BigInteger(bHex, 16);

		return "\u001B[38;2;" + r + ";" + g + ";" + b + "m";

	}

	/**
	 * 
	 * colorise text using ANSI characters
	 * 
	 * @apiNote This does not work with the eclipse console. You must use an
	 *          external console for it to work.
	 * 
	 * @param text - Text to colorise
	 * @param r    - Red value (in decimal)
	 * @param g    - Green value (in decimal)
	 * @param b    - Blue value (in decimal)
	 * @return colorised string
	 */
	public static String colorise(String text, int r, int g, int b) {
		String selectedColor = selectColor(r, g, b);
		return selectedColor + text + CLEAR;
	}

	/**
	 * 
	 * colorise text using ANSI characters
	 * 
	 * @apiNote This does not work with the eclipse console. You must use an
	 *          external console for it to work.
	 * 
	 * @param text  - Text to colorise
	 * @param color - hex value (without the '#')
	 * @return colorised string
	 */
	public static String colorise(String text, String hexValue) {
		String selectedColor = "";

		// if it is a hex value
		if (hexValue.matches("[0-9a-f]{6}$"))
			selectedColor = selectColor(hexValue);

		// if it is an invalid hex value
		else
			selectedColor = CLEAR;

		return selectedColor + text + CLEAR;
	}

}

colors.py

class Colors:

    @staticmethod
    def clear_color():
        return "\033[0m"

    @staticmethod
    def select_color(r, g, b):
        return f"\033[38;2;{r};{g};{b}m"

    @staticmethod
    def select_color_hex(hex_code):
        r = int(f"0x{hex_code[0:2]}", 0)
        g = int(f"0x{hex_code[2:4]}", 0)
        b = int(f"0x{hex_code[4:6]}", 0)

        return Colors.select_color(r, g, b)

    @staticmethod
    def colorise(text, hex_color):
        return f"{Colors.select_color_hex(hex_color)}{text}{Colors.clear_color()}"

colors.sh

###
##
# colors.sh
# 
# convert to ANSI color using this functions
##
# Function synopsis
#
# clear_color (returns an ANSI escape value to revert a color back to normal)
# select_color <red_value> <green_value> <blue_value> (returns ANSI Escape value for that color)
# select_color_hex <hex_value> (returns ANSI escape value for that color)
# colorise <text_to_colorise> <hex_value> (returns colorised text based on hex value)
##
###
#!/bin/bash

function clear_color() {
  echo "\033[0m"
}

function select_color() {
    r=$1
    g=$2
    b=$3
    echo "\033[38;2;${r};${g};${b}m"
}

function select_color_hex() {

    hex_value=$1
    
    rHex=$(awk '{print substr($0, 1, 2)}' <<< $hex_value)
    gHex=$(awk '{print substr($0, 3, 2)}' <<< $hex_value)
    bHex=$(awk '{print substr($0, 5, 2)}' <<< $hex_value)

    r=$(echo "obase=10; ibase=16; ${rHex^^}" | bc)
    g=$(echo "obase=10; ibase=16; ${gHex^^}" | bc)
    b=$(echo "obase=10; ibase=16; ${bHex^^}" | bc)

    echo $(select_color $r $g $b)

}

function colorise_text() {
  text=$1
  color=$2
  echo -e "$(select_color_hex $color)$text$(clear_color)"
}