Color of graphs in SQ app

I don’t understand something about SQ graphs. I always thought that they show red when the starting price on the graph is above the end price, but apparently isn’t always true.
How do they work?

On a side note, I don’t understand the graphs of CHF/EUR and EUR/CHF… If I click CHF/EUR, I see the EUR/CHF graph. or at least that’s what the title says.