Land, vegetated or bare soil, depicts in olive colours in the IR-HRVIS RGB. Due to rather high temperatures of the ground, the blue colour beam does not play a role. HRVIS, contributing with the red and green colour beam, is responsible for the greenish colour of the soil. In fact, the red and green beam have the same intensity. A mixture of red and green normally results in yellow. In fact when yellow gets darker, i.e. the red and the green colour beam are weak but of same intensity, the human eye sees the mixture of both as a green shade.
The image below shows the African sand desert in olive green colours.