The Tri-Luninous thing is just a Sony trademark buzzword. It applied on the 2013 4k sets which used "Color IQ Quantum Dots". For 2014, it applies to the white LED backlight system. It
It is a little technical what that means exactly. LED's produce light at a single wavelength. To get white light, you need red, green and blue. The way white LED's work is they produce light at a blue wavelength at the semiconductor P/N junction. On top of the semiconductor is a layer of phosphor that absorbs some of the blue and emits red and green light wavelengths.
A phosphor is a chemical substance and it produces light at somewhat diffuse wavelengths. It is also hard to get the right wavelengths of red for use in display technology. It is the chemistry that determines the color of light it produces.
The Color IQ Quantum Dot is a lot like a phosphor, but it operates on a different principle than the molecular phosphor. The Quantum dots are tiny particles (nano particles) of cadmium with another material such as zinc sulphide or cadmium selenide coating it, like a candy shell on an M&M. It works a lot like a semiconductor in that the junction between the two layers is what makes it work. The Quantum Dots are manufactured to produce light at precise wavelengths. Chemically, the red and green dots are the same, but the way they are manufactured determines color it produces when blue light strikes it. The emitted wavelengths are also very narrow in spectra, which means the light is more precisely centered on the wavelengths of red, green and blue needed for backlighting the LCD display.
If you took the panel apart, you'd find an array of blue LED's along the side, with a yellow looking glass strip in between the LED's and the plastic light spreader that is behind the LCD itself. The yellow looking glass is what has the Quantum Dots in it and is the origin of the "Triluminous display."
Since "Triluminous" is Sony's own trademark, they can apply to anything they please. For 2014, Sony believes they have white LED's that are worthy of the trademark.