setting a custom color to screen and horizontal alignment

I am creating an app for my project. To make the colors look nicer I want to set custom colors to the buttons, screen and horizontal alignment. I have attached a file of the interface I have created so far and also the blocks I added to try to add custom colors, but its not working. Someone please tell me what I am doing wrong and point me int the wrong direction. 

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From your blocks I cannot see why it should not work. Can you explain what the symptoms are of "it is not working" .
Next time post screen shots, using the insert image button. That would make our life easier.

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It is the empty socket on the HA background Color block that is causing the problem. It needs a colour then everything works as it should.

I used a contrasting colour so you could see it!

Either remove the block and set color to none in the designer or add a colour. 

Or add a fourth item to the colour list and use the value 0. This makes the colour transparent

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+Tim Carter that was one of the problems and also one more issue was that the designer mode wasnt responding to the custom colours that I was adding in the blocks. That made me doubt it. What made the problem worse was that I didnt have a common wifi for the laptop and my mobile to check it in the mobile. Turns out it was working all along, It just wasnt getting reflected in the designer mode of the appinventor.

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Sure. will do from next time. Thanks for your response I can count on this community for some help. 

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