If you are only looking to have 2 blue, illuminated buttons, then the NovaGems would be a good choice. You should have the ~200ma available for them. You could go clear with blue leds, or blue, which come with blue LEDs by default.
The earlier recommendation of using a white LED in a blue button would probably work to some extent, but the color of the LED should be paired to the color of the button. If you tried putting white in a blue button, the button would act as a filter so that only the blue component of the white light would be transmitted and the rest would be blocked. As only a small portion of the white light is actually "blue", it is much less efficient than an LED which is designed to emit it's full output at a more compatible frequency.
Seriously? I just bought two ice buttons and the RGB Drive for each. I really, really don't want to have to add another component at this point. Is there a workaround if you just want the thing to display one color, all the time, so long as power is given to it?
You can wire up one color of the RGB drive directly so it is always on, with no extra components required. Shoot me an email if you need your order changed or would like to explore other options.
RandyT