RGB sensor HOWTO use?
To understand how to use the data, it help to understand how the color sensor works. Let's take a step back for a minute and have a look. The sensitive electrical component here is just a photodiode or phototransistor that lets us measure light intensity.

If we turn all of the LEDs off we are just measuring ambient light. If we turn on just one of the LEDs and hold the sensor close to a surface, we are measuring mostly the reflected light from that one LED (and some ambient light).

When we switch to color mode, it looks like all 3 LEDs are on at the same time, but what is actually happening is that they are being switched in sequence very rapidly. off-red-green-blue-off-red-green-blue-... and so on.

This means the mysterious 4th value, INPUT_BLANK, is the off part of the cycle - it is just measuring ambient light.

You said that you would take intensity as a bonus, but actually that is all you are getting. If you hold the sensor close to a white surface, you should get high values for all 3 colors. If you move the sensor even closer (but not too close), the values will increase. This is because the reflected intensity is getting strong, not because the surface is getting whiter.

This means the RGB values are not like the ones on your computer screen. If you do a web search for robotic vision systems, you will find that RGB just doesn't work. The common practice is to convert the values to HSV (hue-saturation-value). The HSV values can more easily deal with changes in ambient light allowing you to more accurately determine colors.

I am not sure how the normalized and scaled values are calculated in ReadSensorColorEx, but you can play around with them and see if they give you better results for whatever it is that you are trying to do.