Addressable RGB LED Art Project

I am currently now trying to do a little mini project to get my brain into the right gear before I work on my overall project.

so a Knightrider loop (classic and imaginative i know);

What im thinking, is instead of a Uint8Array I could use simply a variable. So for say 5 LED's;
[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,]
Then within the loop i'd need;

• something that increments by 3 each time (so I can move from Red LED to Red LED each time)
  
• Then using the above which goes 0,3,6,9,12 I can tell it to modify the position within my 5 LED variable.
  
• I'd then also need something to reset the previous so? modify i-3 to 0.
  
• SPI2.send4bit.....
  
• Delay
  
  

So what im doing is creating a blanket 5 LED strip of 'off' LED's in a variable, then each time the loop goes round using the 0,3,6,9,12 I can modify the value of the Red LED within that variable and resend the entire thing.

im sure that's rather inelegant but I can come up with more creative ways later ;)