Spark plugs Yamaha 150 carbed

[Blue_Runner]

Here is the story. With saltwater use I like to change the plugs in my 2004 Yamaha 150 every year. Well, I went to buy plugs this year and got the number off one plug so I could buy the new ones. NGK BR8HS-10. So I bought 6 BR8HS-10 plugs. Got home, went to replace them and realized I had 1 BR8HS-10 and FIVE BR7HS-10 in the motor all season. So, my questions....

1) Any repercussions from running like this all this time?
2) Should I go back with BR7HS-10, or BR8HS-10. I think one is hotter, but not smart enough to know which one.

I looked at them and with my untrained eye they all appear to look good and about the same across all 6.

Apparently when I bought them last they accidentally gave me one BR8HS-10 and I did not notice. I am thinking BR7HS-10 is what I want but need expert advice!!!!

p.s. note to self - always double check new plugs are the same before you put them in!