My color vision isn't perfect so I'm not completely sure what you're talking about on that map. I see two things on there that you might be talking about:
1) I see several paths with names that start with "Variante". The similarity with the word "Variant" in English makes me think these are other options for this hike. While these are in red and blue they don't seem quite like what you're asking about.
2) This is a normal topographic map. Follow each bold line (I suspect these are your red lines but I'm not completely sure), you will find an elevation listed. Note a bit to the northeast of the origin point of this trail the line is labeled "600m". From this we can conclude that the trailhead is at approximately 600m above sea level. The last bold line before your destination is labeled "2000m". Note that there are four unlabeled and lighter weight lines between each bold line. (These are probably your blue lines but the lines are fine enough that I am very unsure of their color.) These divide the 100m spacing between bold lines into 20m increments. The lodge at your destination is 2 fine lines above the 2000m line, thus we can conclude that it is 2040 meters above sea level. This seems a much better match for your question but I am not sure the colors are right. These lines make it clear this trail will climb 1420 meters. (Note this closely matches what Google says to the left: 595m to 2041m.)
Also, from those lines we can see that the first part of the climb will be reasonably steep, followed by a walk across the slope that is nearly flat, and then another climb at the end.