Concept:
Tertiary colours are made by mixing primary and secondary colours or by further mixing secondary colours.
Traditional tertiary colour names include:
\[
\text{Olive, Russet, Citrine}
\]
Step 1: Check Olive.
Olive is considered a tertiary colour.
So, it is not the answer.
Step 2: Check Russet.
Russet is also considered a tertiary colour.
So, it is not the answer.
Step 3: Check Litrine/Citrine.
Litrine appears to refer to Citrine, which is a traditional tertiary colour.
So, it is also not the answer.
Step 4: Check Brown.
Brown is a common neutral or mixed colour, but in the traditional tertiary colour set, it is not counted with Olive, Russet and Citrine.
Therefore, Brown is not tertiary in this list.
Hence:
\[
\boxed{\text{(C) Brown}}
\]