Welcome folks today in this blog post we will be building a random color generator with preview inside tkinter using python. All the full source code of the application is given below.

Get Started

In order to get started you need to make an app.py file and copy paste the following code

app.py

#!/usr/bin/env python

import tkinter as Tkinter

FONT = ('courier new',24,'bold')

def main():
    mainWindow = Tkinter.Tk()
    mainWindow.title("Color Preview")
    mainFrame = Tkinter.Frame(mainWindow)
    mainFrame.pack(side=Tkinter.RIGHT, expand=Tkinter.YES, fill=Tkinter.BOTH)
    colorSpace = ColorCanvas(mainWindow)
    redScale   = Tkinter.Scale(mainFrame,orient = Tkinter.HORIZONTAL,from_=0,to=255,relief = Tkinter.RAISED,length=300,sliderlength=20,resolution=1, command=colorSpace.setRed)
    greenScale = Tkinter.Scale(mainFrame,orient = Tkinter.HORIZONTAL,from_=0,to=255,relief = Tkinter.RAISED,length=300,sliderlength=20,resolution=1, command=colorSpace.setGreen)
    blueScale  = Tkinter.Scale(mainFrame,orient = Tkinter.HORIZONTAL,from_=0,to=255,relief = Tkinter.RAISED,length=300,sliderlength=20,resolution=1, command=colorSpace.setBlue)
    redLabel = Tkinter.Label(mainFrame, text="Red")
    greenLabel = Tkinter.Label(mainFrame, text="Green")
    blueLabel = Tkinter.Label(mainFrame, text="Blue")
    colorSpace.addScales(redScale, greenScale, blueScale)
    colorSpace.pack(side=Tkinter.LEFT, fill=Tkinter.BOTH)
    redLabel.pack(side=Tkinter.TOP)
    redScale.pack(side=Tkinter.TOP, expand=Tkinter.YES, fill=Tkinter.Y)
    greenLabel.pack(side=Tkinter.TOP)
    greenScale.pack(side=Tkinter.TOP, expand=Tkinter.YES, fill=Tkinter.Y)
    blueLabel.pack(side=Tkinter.TOP)
    blueScale.pack(side=Tkinter.TOP, expand=Tkinter.YES, fill=Tkinter.Y)
    mainWindow.protocol('WM_DELETE_WINDOW', mainWindow.destroy)
    mainWindow.mainloop()

class ColorCanvas(Tkinter.Canvas):
    def __init__(self, master, *args, **kwargs):
        Tkinter.Canvas.__init__(self, master, *args, **kwargs)
        self.__redScale, self.__greenScale, self.__blueScale = [False] * 3
        self.__t = self.create_text(10, 10, text='', font=FONT, anchor=Tkinter.NW)
        try:
            self.__red   = int(kwargs['background'][1:3], 16)
            self.__green = int(kwargs['background'][3:5], 16)
            self.__blue  = int(kwargs['background'][5:], 16)
        except:
            self.__red, self.__green, self.__blue = [0] * 3

    def addScales(self, redScale, greenScale, blueScale):
        self.__redScale, self.__greenScale, self.__blueScale = redScale, greenScale, blueScale

    def toHex(self, integer):
        if integer < 16:
            return '0%s' % hex(integer)[2:]
        else:
            return '%s' % hex(integer)[2:]

    def showHexColor(self, colorstring):
        if (self.__red + self.__green + self.__blue) / 3 > 128:
            textcolor = '#000000'
        else:
            textcolor = '#ffffff'
        self.itemconfigure(self.__t, text=colorstring, fill=textcolor)

    def setRed(self, event=None):
        if self.__redScale:
            self.__red = self.__redScale.get()
            colorstring = '#%s%s%s' % (self.toHex(self.__red), self.toHex(self.__green), self.toHex(self.__blue))
            self.configure(background=colorstring)
            self.showHexColor(colorstring)

    def setGreen(self, event=None):
        if self.__greenScale:
            self.__green = self.__greenScale.get()
            colorstring = '#%s%s%s' % (self.toHex(self.__red), self.toHex(self.__green), self.toHex(self.__blue))
            self.configure(background=colorstring)
            self.showHexColor(colorstring)

    def setBlue(self, event=None):
        if self.__blueScale:
            self.__blue = self.__blueScale.get()
            colorstring = '#%s%s%s' % (self.toHex(self.__red), self.toHex(self.__green), self.toHex(self.__blue))
            self.configure(background=colorstring)
            self.showHexColor(colorstring)


main()

Now just execute the python script by typing the below command as shown below

python app.py