  In this paper, we use photometric data from the S-PLUS DR4 survey to identify
isolated galaxy pairs and analyse their characteristics and properties. Our
results align with previous spectroscopic studies, particularly in luminosity
function parameters, suggesting a consistent trait among galaxy systems. Our
findings reveal a high fraction of red galaxies across all samples,
irrespective of projected distance, velocity difference, or luminosity ratio.
We found that the proximity of a neighbour to its central galaxy influences its
colour due to environmental effects. We also found that central and neighbour
have different behaviours: central galaxies maintain a stable red colour
regardless of luminosity, while neighbour colours vary based on luminosity
ratios. When the central is significantly brighter, the neighbour tends to be
less red. According to our division in red, blue and mixed pairs, we found
evidence of galactic conformity. Red pair fractions increase in closer pairs
and in pairs of similar luminosity, indicating shared environments promoting
red galaxy formation. Analysing local density, the expected colour-density
relation is of course recovered, but it is strongly determined by the stellar
mass of the pair. In denser environments, the red pair fractions increase, blue
pairs decrease and for mixed pairs it depends on their stellar mass: more
massive mixed pairs decrease their fraction whereas the lower massive ones
increase it. These results shed light on the intricate relationship between
galaxy pairs, their characteristics, and environmental influences on colour,
providing insights into their evolutionary histories.
