Step 1 - Draw two half circles for the Jokers eyes and another smaller inside for his pupils, around the eyes add a parallel line for the black part we're going to color after.
Step 2 - Draw a curved line from one side of the eye to the other just below the eyes and add a small mouth in the middle, draw a few small vertical lines over to show the stitches.
Step 3 - Draw the face line around the eyes and mouth, notice that he has a big forehead.
Step 4 - Draw his ears and the hair shape around his face.
Step 5 - Add a curved vertical line from the forehead to the top of his head and draw a few wavy lines on each side.
Step 6 - Start drawing his jacket with two triangles and add another rectangle below.
Step 7 - Add his arms and hands, start from the shoulder line and draw a rectangle for his arm, divide it into two parts. Draw his thumb and half a circle for the hand, now add a few lines inside the hand to show the fingers.
Step 8 - Inside the jacket, draw the vest he's wearing, start from the upper part and draw a "V" shape, around half the height of the jacket complete the vest and add 4 small circles for the buttons. Add an upside down "V" shape for his tie.
Step 9 - Draw his pants and shoes and add a horizontal line between the legs.
Step 10 - For the coloring part you can use two green shades for his hair and vest. And two purple shades for his jacket and pants.