LED strip WS2812B switching between 12 colors for whole 118 LED strip Help RQ

Hello:

I have a WS2812B LED strip of 118 LEDs. With arduino I wish to manually select from a choice of 12 colors using a rotary encoder and also display a number (of the color) on a 0.95" OLED screen.

The project is a light box for a film enlarger, and the different colors change the contrast of the image on the variable B/W contrast photographic paper. (the attached photo is shown illuminated with non-arduino commercial standalone hardware that is not user programmable)

All the examples for using such a strip I can find are for 'movement' of the LEDs - like theatre chases and changes of color. I just want all LEDs to be one set color at one time.

I have the values (RGB) I require for the 12 colors, but I am having difficulty getting this all to work.

If any member could take the time to point me in the right direction I would be very appreciative.

Hardware: Arduino Uno MEGA, WS2812B LED strip (118 leds), separate 5V power supply (for LEDs), 0.95" OLED color display (96x64 pixels), keyes Rotary encoder

Software: I have the Adafruit_NeoPixel.h library
Thank you so much in anticipation - bambi

All the examples for using such a strip I can find are for 'movement' of the LEDs - like theatre chases and changes of color. I just want all LEDs to be one set color at one time.

So, you can't figure out, from all the examples, how to set the color of one pixel? Perhaps the setPixelColor() method might prove useful.

Setting the color of all pixels simply requires a for loop, changing only the pixel number.

Thanks Paul: Yes that worked - I am on my way