Create a small 30 pixel circle. Select the circle then select the Freehand and Brush Tool (n). Press the Create Brush button. Name the brush Grapes and press OK. Select the kidney shape object with the Freehand and Brush Tool. From the Select an Existing Brush drop down list on the Infobar (to the right of the Create Brush button), select the Grape brush. It will be the second thumbnail image. Click Edit Brush and in the Spacing tabbed section, increase the Spacing slider setting to about 80. Select the Scaling tabbed section. Move the Random slider until the circles are varied in size but so that all the circles overlap. It is important for the next step that there is no open spaces between the circles. Switch back to the Selector Tool (the arrow pointer). With the kidney shape still selected, from the Arrange menu, select Convert Line to Shape. Then from the Arrange menu, select Combine Shapes > Add Shapes, or press Ctrl 1. From the Arrange menu select Ungroup and then Break Shapes. When you do this, the center section shown above in blue dashed outline, will be selected. Press the Delete key on your keyboard. This leaves just the outer shape, which looks similar to a bunch of grapes. Switch to the Fill Tool (g) and with the shape selected, select Fractal Plasma from the Fill Type drop down list. Edit the two colors in the Color Editor (Ctrl e). Click again with the Fill Tool to make the Fractal Resolution and the Fractal Scale text entry boxes appear on the Infobar. Key in the two numbers shown above and press Enter after each to apply the change. Move the Adjust Size of Feather Region slider in the upper right area of the Infobar to 3px or just enter 3 in the text entry box and press Enter  to apply the change. Feathering softens the outside edge of a shape.