I know I should solve this Masyu… But… How should I make this puzzle more colorful?

I know I should solve this Nurikabe variant...
I know I should shade all Masyu circles...
I know I should not let $$2 \times 2$$ unshaded squares appeared...
I know I should solve this Masyu...
I know I should not solve this Masyu...
I know I should remove that appearing white circle...
I know I should make black circle appeared somewhere instead...
I know I should solve this Masyu now...
I know I should solve this Masyu...
I know I should solve this Masyu...
I know I should solve this Masyu...
I know I should solve this Masyu...
I know I should solve this Masyu...
...
But...
The only thing I don't know is...
How should I make this puzzle more colorful?

Nb. There was a fatal error so I decided to "ruin" the passage a bit. Sorry for this!

• Are you sure the 4x4 works as intended? – Deusovi Mar 25 at 3:57

With thanks to @Deusovi for solving the Masyus and doing the hard part.

If you overlay the Masyu solutions on the Nurikabe solution, you will find something interesting:

You notice that

Of the cells which are both (a) new to that size Masyu and (b) not visited by the Masyu line, only one of them is shaded by the Nurikabe.

To extract:

Taking the letters of the shaded squares from the first puzzle, you get R(O)YGBIV, a common abbreviation for the colors of the rainbow.

So to make this Masyu more colorful, you should probably do this:

There, much better.

• Yep, this is correct, well done! For the missing one: rot13(jr fubhyq chg n oynpx pvepyr ng ebj guerr pbyhza sbhe fb gung gur znflh jvyy or havdhryl fbyinoyr, naq gura gur bar juvpu jvyy or rkgenpgrq vf npghnyyl gur juvgr pvepyr vgfrys, juvpu vf yrggre b!) – athin Mar 25 at 22:44

Partial answer - stuck on extraction

Solution to the Nurikabe:

The puzzle is uniquely solvable as a Nurikabe variant: no 2x2 shaded cells, and the cells with circles in them are shaded.

What else is going on?

"I know I should solve this Masyu..." is repeated 7 times -- this is because the thick borders give 7 Masyu puzzles, each embedded in the last! (Well, only six of the seven work: the 4×4 puzzle is unsolvable.)

The solutions:

I'm not sure what to do next; overlaying the solutions to the logic puzzles doesn't look like anything useful. (And the fact that the 4×4 doesn't appear to work is surprising...)

• The text is changed to fix this issue, sorry again! – athin Mar 25 at 4:32