I have recently been using a Gillette 7 o'clock green (super stainless) blade for my Saturday Wildcard shave. I see there is a 7 o'clock yellow blade (sharp edge). What is the difference between the two (besides the colour of the package)? Which one is smoother? Sharper?

I see there is a 7 o'clock Black as well...

ya just gotta buy 'em and try 'em

If I had to pick one it would be the black SP but lots of folks swear by the yellows

........and I like the Russian Green's! I also very much like the 7 O'Clock Blues, but they are hard to find and expensive now.

Bob, tell me you haven't tried the Blacks.
If you have, I'll concede; but if you haven't, I'll send you a pack so you'll realize the greens and blues are wannabes.

Agree: the blacks are great. Which reminds me; I'm all out

I've tried them all. I prefer the Yellows the most, and the Greens the least. Blacks are good too.
1. Yellows- smooth, sharp, long lasting
2. Blues- discontinued. Smooth and sharp
3. Blacks- sharp, not as smooth as the yellows.
4. Greens- Sharp, so, so, smoothness. Not long lasting, for me

I've been pricing the yellows... I see they are not cheap. For anyone that uses the yellows, how do they compare to Astra SPs? I have been using Astra SPs exclusively for months now.

Love the Russian greens. I can easily get 5 shaves out of a blade.

This has been my experience. I like the greens, but really like the yellows.

John-I have tried the Blacks. I was really sticking to the Russians. The Indian Blacks are a very good blade. I still have a few.

There is a YouTube channel called nickshaves. He reviewed the entire 7 o'clock lineup. You should check it out. He rated the green superstainless Russian made as the best. He also rated it as part of his best gear for 2015 as a go to blade. I use these greens as well and I really like them. I actually bought 50 of them and was using them before I saw his video. Hope this helps.

All of this is subjective. Just try all of them, and find the ones you like the most.

Thanks Ryan...I will check out Nick's video. I find it difficult to distinguish between different blades. Even my Astra SPs that I use every day vary based on how many shaves I have on each blade. So the consistency changes. I have been using a 7 o'clock green blade lately and have found it quite nice. And yes, I know blades are the ultimate YMMV...
Late Edit: Sorry...I meant to respond to @Jbrew comment about Nick Shaves. Apologies.

Just watched Nick's video on the 7 o'clock Super Stainless blade and he raved about this blade. I must dig those out of my drawer and use them for a couple of weeks...

I agree with @PLANofMAN that razors are an individual thing. What works for me may not work for someone else. I did like the nickshaves videos because he offered his thoughts on sharpness and smoothness of the blades. Again taken with a grain of salt. He has a best of 2015 video as well which featured the Russian green 7s for those who are interested.

All I can say is that I've just finished shave #21 with my Gillette 7 O'clock Yellow.
Still smooth shaving, and delivers excellent shaves. No sign of tugging, yet.
(This is why I prefer the Yellows)