Ryu: His Super saiyan form already merged with the God Ki in his battle with Beerus, it's actually super saiyan blue before the change in color happened.
The Super saiyan blue is like a side effect of the combination, Goku and Vegeta was training their God Ki in base form, it somehow resulted in the Blue Aura.
Also Imma change the system a bit
- Goku/Vegeta Base form (until now, they can either use both Normal Ki or God Ki whenever they want, that's why i mentioned earlier that "We are not sure when will they use God Ki or normal Ki in their base form", but we're sure to know that in episode 42 is that Goku did USE God Ki in his base form against Beerus)
- Goku/Vegeta Base form + God Ki (Normal Ki and God Ki both work simultaneously in their body, God Ki boosted up Normal Ki to a higher level, that's the reason why Krillin and Gohan can still sense Goku's Ki)
- Goku//Vegeta Regular Super Saiyan (normal Ki) (in the beginning of universe 6 tournament)
- Goku Super Saiyan + God Ki (in his battle with Beerus, imperfect, Used both Normal Ki and God Ki in supersaiyan state) *only used by goku and no longer exists until the side effect occurs
- Goku/Vegeta Super Saiyan Blue (Super saiyan + God Ki, the same as above but more perfect, no longer utilise Normal Ki, the God Ki takes over)
- Goku Supersaiyan blue + kaioken
- Goku supersaiyan blue + kaioken x10
EDIT: Vegeta was using Normal SSJ against Magetta , Goku was also using Normal SSJ against Frost (no God Ki). To be honest, If Goku were to use his God Ki in base form, he could literally knock out Frost even in 1 hit but instead he was using normal Ki both in Base and Super saiyan state, same goes to Vegeta.