Change Color Associated with Transparency? ok so here is my problem. in this picture i want the White outside the Blue to be Transparent, and the White inside the Blue to to White.

this is as far as i get when just using the Transparent BSDF.



As you can see, both White areas are Transparent. is there any way that i can make the Outter Area the Only Transparent one??

EDIT 1:

after using cegaton's Advice i set up the nodes and such according to the 4th example,however the full sphere seems to be transparent now, regardless of color placed on the texture.


EDIT 2:
i get the feeling this may just be too advanced for my level of skill in this current time period... perhaps somethin like this might be easier.

In this example im using a stock lightning effect i found off Google. is there any way i can have this so that the black parts are see through, while keeping the rest of the image the same?

FINAL EDIT:

turns out im an idiot and just didnt realize the Alpha channel on the Texture got removed completely some how....quick trip to Gimp and 5 minutes later i got the results i wanted
Let's say you have an image with an alpha channel:



Which in turn, is nothing but a mask: an image with a black and white channel that determines the opacity of the RGB information. Black (0) is considered transparent, white (1) opaque.



If one were to use the image as color for the texture we get an opaque texture, because the alpha channel is not being used, just the RGB information.



Adding a transparent shader and using the alpha information to control the mix will make the black (0) pixels of the alpha channel be transparent and the white ones opaque (1).



If you don't want to use the color information of the image, but want to keep the mask to control the transparency, then just set the color of the shader to whatever color you want and use the alpha channel to determine the mix with a transparent shader.



If your image has no alpha channel you could still use the color information as mask:

In this case, since the mask information is in the blue channel, you can use any of the other two channels (red or green) to determine the mix between diffuse and transparent.





But your confusion is coming from thinking of transparency.

If what you want to do is mix colors (with no shader being transparent) then use the image as mask to mix colors.