I want the alpha channel color to be white instead of black

[#1]

I want the alpha channel color to be white instead of black because my objects also have black color, so they are not presenting well.

Is it possible to have an alpha channel after exporting and see white background instead of black?

Thanks !

[#2]

I want the alpha channel color to be white instead of black because my objects also have black color, so they are not presenting well.

Is it possible to have an alpha channel after exporting and see white background instead of black?

Thanks !

[#3]

In the video output secrion in The redering settings: select "straight" from colors instead of premultiplied 

[#4]

Thanks

[#5 · Accepted solution]

I don't know if I understand you, but to change the composition background color from black to white you can do that from composition settings, and even you will still get an alpha channel as usual after exporting 

[#6]

Changing the Composition Background to white WILL NOT add white pixels to the transparent areas of your comp and it will render as Black with almost every video format you choose. If you want a white background you need to put a white solid or white shape layer at the bottom of your comp. 

The only real reason a professional would change the background color of the comp would be to render a video that has an alpha channel that needs to be Premultiplied with the specific color so the anti-aliased edges would have a better chance to blend with a new background without further manipulation. This is an extremely rare problem for anyone to have. After Effects, Premiere Pro, Davinci, Inferno, Flame, all video production apps, and even all 3D apps that I have ever used use Straight Alpha as their compositing mode, so rendering pre-multiplied with a colored background is indeed a very odd thing to have to do.