Develop Reference

Change Launch Screen/Splash Screen color and image

The app itself works completely fine. My question is that on the launching of the app itself, the screen is the Unity default blue for a quick second or so before changing to the black of my first scene.
How do I change this color to be black on startup?

You can change this by going to File --> Build Settings --> Player Settings --> Splash Image --> Background --> Background Color.
From there you can change the background color. You can also change the image, animation type and overlay opacity from there.
Note that there are things you may not be able to change there unless you have Pro license.
EDIT:
Updated to be more detailed of where to change stuff
First change the Splash Image:
There are more options for iOS platform but this settings can still be found in the menu I mentioned above.
If iOS, select iOS as your platform and you can change your Background Color from there:
You should then change the Lunch Screen type from there. Set it to None if you want it to be gone.
If the color does not still change, you can create a Texture with a color of your choice and add it to the Mobile Splash Screen slot:

I believe the OP was looking for the Background Color of the Launch Screens as indicated in these screenshots.
This is taken from an iOS build setting panel. We've observed odd behavior with no textures at all (even though that is what we want), so we use single-pixel, solid-color images as well as a background color to match.
These fields are not made available in the PC/Android build windows, so not 100% sure what the equivalent would be - beyond using flat-colored images. Either way, it is these elements that are used prior to loading your scenes.

I think you are talking about the camera background color. You can set it up in your main camera to black. You can find the camera documentation here.

Wrong size of "unplated" icon is used

I am writing a UWP app that includes an "unplated" icon at the 32x32 size (file name Square44x44Logo.targetsize-32_altform-unplated.png). I also have the same icon at the 24x24 size (file name Square44x44Logo.targetsize-24_altform-unplated.png). I also have the same two sizes in non-"unplated" variants. However, when I build and run my app, the icon used in the taskbar (and only the taskbar) is of an incorrect size. The 24x24 icon is used, instead of the 32x32 icon, resulting in the icon appearing visibly smaller than the others in the taskbar. See picture below.
I have followed the advice in this question, to no effect.

The 24x24 icon is used, instead of the 32x32 icon, resulting in the icon appearing visibly smaller than the others in the taskbar.
Your icon looks smaller than others might because it's rectangle. It has fewer number of pixels on the vertical, showing it in a "unplated" fashion would make it "looks" smaller.
Below is a screenshot of the zoomed image, it shows that your icon has the same width with another two icons.
In this case, I suggest you using the “plated” icon to see if your icon is the same size of others.
Windows 10 introduces an evolution of the existing scaling model. In addition to scaling vector content, there is a unified set of scale factors that provides a consistent size for UI elements across a variety of screen sizes and display resolutions.
For more information, see to Guidelines for tile and icon assets.

Changing size of Notify Icon

As we know when we use notifyicon control in c# and place it in systemtray and it is displayed, windows overrides its size and make it 16*16 so can we somehow change its size? make it little bigger like system "date and time" display or like "input method type" in windows 8. I want to display certain text there.
Thanks in adv.

The system draws the icon, and it decides what size it is. For what it is worth, notification icons are the system's small icon size. So in fact you should not assume that they will be 16px icons. For font scalings larger than 100% the small icon size will be larger than 16px.
At the Win32 level, the application supplies an HICON, and the system draws that. If it needs to resize it, it will. You cannot custom draw in the notification area.
Imagine if applications could custom draw in the notification area? All it would take would be for a couple of applications to decide that they were so awesomely important that they had to custom draw large amounts of information. And then there'd be no room left for the rest of the taskbar.
So, the bottom line here is that you will need to find some other UI approach to solve your problem.

Form icon resized wrong

There is quite a lot of discussions about icons in .NET and they still seem to give different people different problems. Still I dind't find an answer for my case.
I'm writing an application in Visual Studio which runs in Windows 7.
I set application icon in Project/Properties/Application. Nope, still default icon used in taskbar.
So I read that I should set the same icon for the form too.It works now, but still not perfect.
If I use icon 48x48 pictures it looks okay in taskbar but is badly resized to 16x16 at form's top.
If I use 16x16 it looks okay at form's top but is badly resized with big square pixels in taskbar.
Is there any way to set two different icons for a form? one for form's top and another for taskbar? Or maybe some other approach would work?

You need to use a .ico file that contains multiple versions of the icon. The system embeds in your executable file these different versions in what is known as an icon group using the RT_GROUP_ICON resource type.
The documentation on MSDN list the sizes that are required to be included in the icon:
Application icons and Control Panel items: The full set includes 16x16, 32x32, 48x48, and 256x256 (code scales between 32 and 256). The .ico file format is required. For Classic Mode, the full set is 16x16, 24x24, 32x32, 48x48 and 64x64.
Note that the 256px icons can (and should) be PNG icons to keep the size manageable.
You'll need to find an icon editor that can make .ico files that contain multiple versions of the image.
You might find this question helpful: Which icon sizes should my Windows application's icon include?

An icon file (.ico) can contain many different sizes of icons
Wikipedia Reference ". ICO files contain one or more small images at multiple sizes and color depths, such that they may be scaled appropriately".
So you need to specify all sizes you want to display cleanly. Namely: 16x16, 32x32 and 48x48
Get yourself a copy of IcoFx of another good icon editing program that allows multiple sizes (and colour depths) to be saves into one ico file

How do the new Windows 8 App logos work?

In the Windows 8 App manifest file, I see a handful of different fields. For example:
Logo
Wide Logo
Small Logo
Store Logo
Badge Logo
Splash Screen
Each of these also have their own scaled assets, too.
So, if I want to scale my app's image (since I usually create graphics with Fireworks or Illustrator), how do I properly set all of the images for my app? I would like to support all of the scales possible by re-sizing my image to fit the scaled values...or am I supposed to go about it differently by creating an image with multiple sub-scales within it? Is there a name for that? I'm a little bit confused here...essentially, how does this all work?

Here is a blog post from Jerry Nixon about logo resizing, he use Expression Design but it should be similar with Fireworks or Illustrator: http://blog.jerrynixon.com/2013/09/windows-81-says-forget-all-that-design.html

Check out this MSDN post
Choosing your app images
But I would recommend you to check out Jerry Nixon's this article.
Windows 8 apps need 28 logo varietals; enter Expression Design