Color difference

[NaGaNn 0]

Hi guys ! Hope you are fine, I just noticed that there is a color difference on the first layer for everything I try to print, do you know what is the cause of this ?

 

I use an ultimaker 2 printer, and the build plate is properly levelled.

Edited July 12 by NaGaNn

[NaGaNn 0]

Also ( I don't think this needs to create another topic) I have this little issue at the end of every print I make : the nozzle doesn't go up directly at the end of the print so it keep extruding material and create this non desirable thing. Any solutions ?

[ahoeben 1,845]

Looks like this is not a color difference, but a transparency difference, caused by a varying thickness. This varying thickness is caused by an uneven distance from the nozzle to the buildplate, ie an uneven buildplate. To mitigate the issue, you could try to increase your initial layer height in Cura, but it would be better to make sure the bed is actually level and flat.