We decided to adopt the new color for our Ultra and Histo knives from April 2022. Ultra will be navy blue from green. Histo will be black from red(rose). See the difference between them on the left picture. There are several reasons to change colors this time. The biggest one is seeing sections clearer than previous colors under any thicknesses.

We got some feedback from our customers that green and red(rose) are difficult to see interference color on several range of thickness of the sections.
Once we choose dark colors and checked thin to thick sections looking every 10 nm, those issues are solved.
We know that some other users don’t mind our original colors even any thicknesses.
Therefore, we keep making those previous green and red(rose) from now on.
If you want those original colors, and you designate it when you order knives?
If you don’t mention about colors, we provide Ultra as navy blue and Histo as black to you.
This basic rule is applied to our JUMBO and JUMBO WT, too.
*MGH, Cryo and Trim will not change those colors at this moment.