Electrical – Wiring RGB Vandal Switch as PC Power Button

More data please.
Power, target, distance, size ... application ?

Fresnel lenses have the advantage of beam shaping with relatively minor optical losses - about 10% typically. The same applies to TIR lenses and reflectors - both of which MAY do what you want. White paper achieves its superior result with a very high optical loss. This may be unimportant or crucial depending on application.

Just poke around with a 30V power supply with a 1K resistor in series, as Starblue suggests and you'll quickly figure it out (I suggest the resistor because the output capacitor of even a current-limited power supply could damage the LEDs conceivably)

Probably 3 strings of series or series/parallel with a common. Whether it's common anode or cathode is unknown.

Chances are the top strip in your photo is the common, and the bottom left is red and the other two are green and blue (maybe not that order for green and blue).

^{simulate this circuit – Schematic created using CircuitLab}

You need to limit the operating current into the LEDs to less than the smaller of the rated current and the maximum allowed by the power dissipation. As in the comments if you power this up at anywhere near the claimed 20W input power it will see perhaps 18W of heating and will expire in short order.