Pie charts are usually in the domain of spreadsheet or accounting and mathematics software, but there are no rules against "baking" your own. Using a graphics program, such as Adobe Photoshop, you can create a pie chart from scratch and enjoy full control over both the size of the pie pieces and their colours. Create a tonal pie chart or one with colours that are exact opposites, according to your pie chart requirements.
Open Photoshop. Pull down the "File" menu and click "New." Type "PieChart" into the "Name" box. Type the pie chart canvas dimensions, such as "6" for both the "Width" and "Height." Click "inches" for each drop-down menu. Click the "OK" button.
Click the "Ellipse Tool" on the bottom of the "Tools" pane; it looks like a circle. If you do not see the circle, right-click an icon of a rectangle, star or line and select "Ellipse Tool" from the flyout menu.
Click into the "Color" box on the toolbar at the top of the screen. Select a colour for the pie chart; pick a colour you'll want for at least one of the pie pieces.
Click the cursor into the top-left corner of the "PieChart" box, press and hold down the "Shift" key on the keyboard and drag to the bottom-right corner. Release the "Shift" key and a filled-in circle appears.
Click the "New Layer" icon, which looks like a sticky note with a bent edge, on the "Layers" palette on the right side of the screen.
Right-click the "Ellipse Tool" and select the "Line Tool" option. Choose a contrasting colour from the "Color" box on the toolbar. Press and hold down the "Shift" key. Draw a line from the top-middle of the circle to the bottom middle, breaking it into two halves. Don't worry if the line goes into the white space or off into the grey of the Photoshop work area.
Draw a line from the left middle of the circle to the right middle, so now the circle is in four quarters. Continue drawing lines from side to side, making sure they all bisect the circle in its middle, until you have the correct number of pie pieces, though they are currently all the same colour. Note: For differently-sized (non-equal) pie-pieces, draw the lines according to the percentages you have for the chart, but they still must bisect the middle.
Right-click the Shape layer in the "Layers" palette with all the lines. Select "Rasterize Layer." Click "Yes" at any warning windows. Click the lined icon in the "Layers" palette's top-right corner and select "Flatten Image."
Double-click the top-left square of the "Color Picker" at the bottom of the "Tools" pane. Choose a colour for one of the pie pieces. Click the "Paint Bucket," in the middle of the "Tools" pane, and click that pie piece to fill it with colour.
Change paint colours in the "Color Picker" and continue to fill the pie with the different chart colours until completed.
Click the "File" menu, select "Save As," and click the "Save" button.