First forget about thinking of color as Hex values. That is not how blender works.
The same color will change depending of the amount of light that hits the surface of objects. Also the final value will depend as well on the kind of color transform chosen in the color management settings.
Let's start by asking what is "white"?
"White" is not a color, it is just the limit of what the display can deal with, in other words it is when the data has reached the top of the scale (from 0.0 or 100%) in all three channels. Most likely you need to increase the intensity of the light sources to reach that value.
Read:
Make texture visible in sunlight
and
Render with a wider dynamic range in cycles to produce photorealistic looking images
and
How do I stop my white background from becoming grey due to lighting?
As for the reflections on the glass, well, glass is both transparent and reflective, so you will have to control the elements that get reflected on it. If you don't have any reflections then the surface will no longer look like glass and the viewer will think that there is nothing there.
Read:
How to turn off reflections on glass