It's cluttered. You have character forms overlapping and reply of different tonal values to tell them apart. The 'F' appears to be the prominent character/name in the logo. Also the text at the bottom is too small in relation to the ones above. When the logo is shown at smaller sizes, you won't be able to read the name.
Work only in black and white
Ensure all text is equally legible
Try the name in the same/a similar serif font to the large letters.
Thanks for the Feedback:
The F stand for the Name of the client, that's why it is more important than the other letters.
Black and white would also be prefered but the customer wants blue and silver (will be printed in silver, not grey)
I try to organise it more.
Whilst you're designing it work in a single colour. It's not a good idea to rely on colour or a print technique for a logo to 'work'. If you design in just one colour you can clearly see how legible the overall logo is.
If you're doomed to those three colours because of their branding, you're heavily restricted because of the tone clash (the grey/silver and the heavy royal blue) - so to work with what you've got:
I would suggest maybe using the white as the background colour to help keep any similar elements from butting up against each other too much. It's easier to apply to letterheads/printed items that way too.
Are they happy with you making the left-to-right order of the initials (AFN) and the order names (FAN) consistent? If so, I would try that and in doing so, perhaps consider using one consistent font?
I would with one point mentioned by @Jri i.e. using white color as the background color and using remaining two color in the logo. One suggestion would be to use one color in the background, one color in the logo text and another color in the full form of the logo. Also you can use some other sleek font rather than the existing one.