In this tutorial, you will learn on you how to create a colorful abstract vector background in Photoshop using gradients, brushes and Curves adjustment layer.

Start working by creating a new document in Adobe Photoshop CS5 with the size 1920 px by 1200 px (RGB color mode) at a resolution of 72 pixels/inch. Create a new layer and select the Soft Round brush from Brush Tool. Use this brush to paint the background layer as shown. The brush color should be of this color #C29B40. Choose the Pen Tool, set the drawing mode on Shape Layers in Options bar and draw the next black shape as shown. Using the same tool, represent another shape of white color this time. Set Fill to 42% for this layer. Click on Add a layer style icon from bottom part of the Layers panel and select Inner Shadow. Next, select again the Pen Tool to represent the next shape inside of the already made one. Its color should be #63BA59. Click on Add a layer style icon from bottom part of the Layers panel and select Gradient Overlay. Click in the color bar to open the Gradient Editor and set the color stops as shown. Click OK to close the Gradient Editor dialog box.

Then we will make another shape, under the recently made one, applying the same Pen Tool. Click on Add a layer style icon from bottom part of the Layers panel and select Drop Shadow. Add Inner Shadow and apply Gradient Overlay. Click in the color bar to open the Gradient Editor and set the color stops as shown. Click OK to close the Gradient Editor dialog box. Create the next new layer and select the Soft Round brush from Brush Tool. Use this brush to paint the background with the color #600901 and Opacity to 20%. Create a new layer and apply the earlier taken brush to paint the background with #441A16 color. Create the next new layer and take the Soft Round brush. Use this brush to paint the left bottom corner with this color #100B1A. Create a new layer and apply here the Soft Round brush too which  applied previously to paint the canvas in white; brush Opacity should be 20%. Create a new layer again and apply here the Soft Round brush to paint the canvas on its bottom part using the color code of #80BDB9. Create a new layer and apply the Soft Round brush of white color with Opacity of 20%) to paint the canvas on the top right part. Set the Blending mode for this layer to Overlay. That will end the steps. Hopefully that helps!