Flux-colour ratio figure log (F₁₆₀) vs. log (F₁₆₀/F₂₅₀) showing the Herschel photometry of all sources with required photometry detected in the field. The grey triangles represent the Luhman et al. (2008) class II objects, the class I objects are shown by black circles. The flat spectrum objects are marked by asterisks. The inverted triangles mark the transition disc objects. The Herschel detections with a counterpart in the Belloche et al. (2011) catalogue are marked with open squares. These objects may be class 0 sources or starless/prestellar cores. No trend in magnitude is present, however the known YSOs exhibit a bluer colour than the candidate cores. Note that redward is to the left in this diagram.