Faber Castell Polychromos used to come in a large set size of 100 colored pencils. This set was replaced with a set of 120 colored pencils by Faber Castell where 23 new colors were introduced. Three colors were reitred being Soft Black, Light Violet and Light Blue. Those pencils are very difficult to come by nowadays.
I have the Faber Castell Polychromos Light Violet and Light Blue. After going through a number of my pencil sets, it seems that there are some pencils from other brands that are similar or could be tinted to look similar to the Light Violet and Light Blue Polychromos pencils.
You can see my swatch below and in my video above, I give my top three pencils you can substitute for these colors.
Happy coloring x