Loshen, this is the note I dug out from my late father's note book. For us to think why in the past experiments we had so much issues:
Any slide film that can be developed in Singapore (aka 1960-1970) will have issues with Black Purple (red) and Grey.
The film coating is thin. In theory, the black section should not pass light at all, but in reality, the darkest still pass light.
Hence, black or hair may appear like deep deep blue. If the Kodakchrome is over exposed, black may even appear as blue.
Purple is another challenge, will always biased towards pink or greenish purple.
Grey is the worse, impossible to be free from other colour contamination.
All these were due to the film emulsion structure of Kodakchrome devloped in Singapore (60-70) using one one step developer.
The film already contains colour emulsion layers and dye. As the dye is organic, changes will always happen.
Hence film cannot be exposed to heat, moisture, and thermal cycle. And must be developed Asap to preserve true colour.
For Kodakchrome that must be developed by Kodak using dedicated machines, the color were added during the developing process.
Before development, film has no color, like B&W.
Development process usese 3 colour development to develop 3 layers of color emulsion layers. Require dedicated machine with strict control.
The final film density is very high, colour is much more saturated. Black, Purple and Grey are nearly ideal.
(I look at some old 70s Kodakchrome, the film appears thicker).
Looks like your test strip may never arrive at what you want, because your starting baseline may already shifted already.