I meant IR filter and mixed up wavelength and frequency lol is using the IR pump the only way to get green lasers/a lot of these other colors, or are there diodes that put out each wavelength? Is there a reason that they are such specific wavelengths and not 533 or 531?
TL;DR: kind of, no, and yes.
Diodes output specific wavelengths, the most common being:
375nm, 405nm, 445nm, 473nm, 485nm, 520(ish)nm, 635nm, 640nm, 650nm, 670nm(old), 671nm, 760nm, 785nm, 808nm, 848nm, 980nm, 1.064μm, 1.31μm, 1.48μm, 1.512μm, 1.55μm, 1.625μm, 1.654μm, 1.877μm, 2.004μm, 2.330μm, 2.680μm, 3.03μm, and last but not least, 3.33μm. (1μm = 1000nm)
I've probably missed some, but it doesn't really matter. As you can see, there really aren't many wavelengths for standard diodes. Some of the wavelengths can be changed with temperature, but it takes a huge shift in temperature for a tiny shift in wavelength. Plus, the human eye can't see half of the wavelengths listed. DPSS lasers provide a slightly larger spectrum of colors. They operate by changing the wavelength of light by passing it through a set crystals. For example, the way a typical red laser works is by powering a red diode. The way a green (532 not 520) laser pointer works is by pumping an Nd:YVO4 crystal (or YAG, but YVO4 is more common in pointers.) with one or more 808nm diodes, which creates light at 1.064μm. The light is then directed into another crystal, usually KTP, and 2 of the 1.064μm photons collide in the crystal to make a 532nm photon. (1064 ÷ 2 = 532) Shifting the wavelength of DPSS lasers with temperature doesn't work. That's why the wavelengths are so specific, but they are the only way to obtain wavelengths that are yellow and the extremely rare orange in pointer form. But there aren't just diode and DPSS lasers out there, for instance you can obtain pretty much any wavelength you want with a dye laser, and the Ti:sapphire is very tune-able as well. There are also gas lasers and metal vapor lasers that emit different wavelengths. Also in regards to your other question, there are 520nm diodes, which are green.
(Sorry for the long reply)