Blending and spinning a shaded rainbow using just red, yellow, blue and black merino wool

I spun this yarn during TDF 2021, but it is part of an ongoing project where I’m experimenting with blending a spectrum of wool colours and then keeping a record of how I made each rainbow, so that I can reproduce any colour easily.
For this yarn I began with 24 colours, evenly blended around the red/yellow/blue colour wheel.

(Copied from my answers in the comments as I really should have put it in the description):-

To get the first colour wheel you see, I started with 100% red, then blended 7 parts red to 1 part yellow, continuing with 6:2, 5:3, 4:4, 3:5, 2:6, 1:7 until I got to 100% yellow. I then repeated the same with yellow and blue, then blue and red.

All of these colours were then blended at a 7:3 ratio with black to get this finished shaded rainbow.

This has been an ongoing project that I started just before the beginning of the pandemic, I was originally trying to find out how much white I needed to add to a saturated colour to get a pastel colour for a blanket I’m making, but it has kind of spiralled out of control!

I began by mixing together 100g of red, yellow and blue in varying proportions to get my original red/yellow/blue colour wheel and then arbitrarily added varying ratios of white fibre until I got down to the pastel shade I was originally trying to find. When my fibre got down to between 5 and 7g of each colour, I decided to go for this 70:30 ratio of colour to black as I knew this was a shade I wanted to sample for another project.

My maths wasn’t primarily based on weight, rather percentages and ratios. When you hackle blend, there is almost always waste and so I ended up with varying weights of each colour. I weighed each colour, divided that weight by 70 and then multiplied that figure by 30 to work out how much black to add.
There is 429m and 132g of chain plied yarn here, so not masses, but I mainly spun it to sample the colours.

It took about 40 minutes to blend the black into each colour, but that doesn’t include the original blending of the red/yellow/blue colour wheel I did.

This project has never been about the final yarn though. It’s always been more about working out how much black or white I need to add to saturated colour to get the shade or tint that I want and holding onto those results for future reference so that I can replicate it at a later date.

0:00 Introduction
0:08 Showing the initial blend of 24 colours that I began with to make my shaded rainbow
0:16 beginning to add black to one of the rainbow colours
0:29 drafting the blue fibres off the hackle with a diz
0:58 Adding the blue/green fibre to the rest of my shaded rainbow
1:21 spinning the singles
1:35 The Electric Eel Wheel 5 spinning around
1:51 The Electric Eel Wheel 5 at every different coloured layer
1:58 Image of hand made bobbin ends
2:05 Chain-plied ball
2:12 Resin bobbin end of plied rainbow yarn
2:24 Mound of rainbow yarn
2:29 Rainbow yarn wound into a cake ball
2:35 24 separate colours of shaded rainbow yarn
2:54 24 shaded rainbow colours wound onto shade cards for future reference