Vanishing Colours in the City of Emotions

In the City of Emotions, every street had its own colour - the houses on Orange Street were always cheerful, while Green Hope Square bustled with tranquillity. Zosia loved to watch from her window as the colours changed slightly each day, depending on the mood of the residents. One gloomy morning, however, something was different. Instead of a rainbow of colours, a grey mist stretched in front of Zosia's house, and the yellow sun looked as if someone had erased it with an eraser. - Tymek! - cried the girl to her little brother. - Can you also see that everything is fading? Tymek ran out of the room holding his favourite purple ball, which was now... grey! - My ball is sick! - he shouted in despair. - What has happened to our town? In the kitchen, Mum was struggling to bake rainbow cupcakes for the festival. The icing was colourless and she looked dim. - I think there's something going on, kids. No one is admitting to any emotion. I'm assuming people have started hiding how they feel.... Zosia looked out of the window at her sad neighbour, who usually shared a happy smile but today avoided the gaze of others. - This must be it! - she said suddenly. - When we hide our emotions, the colours disappear! Tymek looked at his sister with concern and excitement at the same time. - We have to do something about it! Maybe if we find the biggest hidden sadness, everything will return to normal? Zosia and Tymek decided to set out to find the source of the greyness. On the street, they met a mysterious boy in a dark blue coat, who held in his hands a jar full of... sparkling tears? - Are you the one taking the colours away? - asked Tymek boldly. The boy looked at them seriously and....