looks better in the modified version. And the font is really small.
it uses a 6x4 matrix for the digits.
Well this is really small. As all you do with the display is showing a single row of digits the font should use the complete 8x8 matrix.
You haven't said anything about the driver-chip of the matrix.
I have a similar 8x8 matrix which uses the MAX7219-driver-chip.
I use this library for it
I use the code based on the marquee example
If you don't want the text/digits to move you can remove the logic that does the horizontal scolling.