We find in the Torah and Chazal , the colour “Adom” can mean a) the actual red colour
(red rose) b) the red family, colour (brown , orange etc.)
Bereishis 25 – 30 Haliteini noh min Ha’adom Ha’adom Hazeh
It is called red lentils, but its colour is brown.
Zecharya 1 – 8 Ish Rochev Al Sus Adom – Susim Adumim (A man riding on a red horse-red horses)
There are no red horses .There are brown horses.
Succah 35b An Esrog that was peeled and looks like a red date. Rashi says All peeled fruits
Nehefach l’admimus (turn red).
Peeled or cut fruits turn brown not red.
Bechoros 6a Rashi Stam Susim Adumim (horses are usually red)
Never heard of red horses
The colour of a Parah Aduma was brown .The uniqueness of the P.A. was not that it
was red. It was unique by being completely brown, not having two strands of hair in
a different colour other than brown.