Analysis of the stellar populations of the Helmi streams. Left: distribution in the CaMD of the stars classified as part of the Helmi streams (clusters #60 and #61) colour-coded according to the colour distance to the best-fitting isochrone (black dashed line, see Sect. 3.1). Center: histograms of the difference in colour for stars in clusters #60 and #61, and showing compatible distributions with a KS p-value of ∼0.6. Right: metallicity distribution function from LAMOST LRS for both clusters (p-value of 0.99). Error bars were computed assuming Poisson statistics.