Daniel Smith Hansa Yellow Light uses PY3 which is Arylide Yellow 10G, a high-tinting, organic pigment.
This colour is transparent, moderately staining and non-granulating. This is a light and bright yellow. A yellow that seems to be even cooler in colour temperature compared to Daniel Smith Lemon Yellow (PY175) because there is a slight hint of green in it. Some manufacturers make their Lemon Yellow from PY3.
Hansa Yellow Light is marginally lightfast with a rating of 2 out of 4, where 1 is excellent and 4 is fugitive.
Hansa Yellow Medium uses PY97 which is Arylide Yellow FGL. This yellow is slightly warmer compared to the Light version and has similar characteristics such as semi-transparent, medium staining and non granulating. It's more lightfast than the Light version.
The colour that looks quite similar to it would be Azo Yellow (PY151) which seems to be slightly more intense than Hansa Yellow Medium. This paint is made with Benzimidazolone Yellow, is very lightfast, and is from Series 3 so it's even more expensive than Series 2 Hansa Yellow Medium.
New Gamboge. I probably won't be able to tell the difference between these two from a blind test.
The real Hansa Yellow Deep looks different from the colour on the tube's label.
Mixing Hansa Yellow Light and Medium with Phthalo Blue (GS) will give you the most vibrant green. That's not surprising from a cool yellow and cool blue. You can get beautiful mixes with Cerulean Blue Chromium too where you can see granulation and the individual colours in the mix.
Mixing Hansa Yellow Deep with Phthalo Blue (GS) will produce a darker more muted green. And with French Ultramarine and Cerulean Blue Chromium, the result is a colour that's more brown than green. The Cerulean Blue Chromium mix is still pretty interesting because of the colour separation.
To get a vibrant orange, you'll need a warm yellow and warm red. So it's not surprising that the most vibrant orange from these mixes is from Hansa Yellow Deep and Pyrrol Scarlet.
Actually with Pyrrol Scarlet, which is such an intense warm red, you can get an orange with a cool yellow.
If I can only include two yellows in my palette, Hansa Yellow Deep will be one of them. As for Hansa Yellow Light and Medium, it's really a 50-50 toss up for me. Their mixes look quite similar.
Links above at Amazon affiliate links. You can also find Daniel Smith watercolor on Jackson's Art (UK).