In the beginning I used a 1,9" TFT (320x170) display and an upgrade to a 2" TFT (320x240). This was quite a rabbit hole. Two moths later and an extra breakout board for a 22-pin FFC/FPC connector for flat cables i found out there are 3 types of 2"TFT display available (on AliExpress). The two displays I Initial bought didn't just not work. I had the datasheets and pinouts, but nothing worked out. Finally i found one that worked without extra components like R's or C's attached to any datalines. 

But those extra 0.1 " display and pixels were worth the time.

10 tiny Neopixels next to the display gives dependent on the measuring mode extra information.

-In Audio mode the amplitude will show up. 
-In Spec. mode the RGB input passes through to show the color measured 
-In 2d-LIDAER mode there is no output at this moment

Many revisions have been ordered and it was a lot of fun. Every revision got a different color from the PCB-manufacturer to find my favorite. 

Adding another layer in KiCAD for the outline of the design including holes were the sensors can "see" through and exporting and edit them in inkscape gave me files for acrylic plates that become the protective "case".

Adding a battery makes this thing portable. The charging circuit and usb socket is not included and needs to be connected to pins in the front.