icons

Instead of images, you can use font icons.
The advantage is that you can change the icon color in company-box.
Also, there are many icons available with icons-in-terminal

Please visit icons-in-terminal page and follow the instruction to install it.
If you are on windows or another system where the installation script failed, you just need to install build/icons-in-terminal.ttf and add build/icons-in-terminal.el in your load-path

Then you can set the following variables:

(setq company-box-icons-unknown 'fa_question_circle)

(setq company-box-icons-elisp
   '((fa_tag :face font-lock-function-name-face) ;; Function
     (fa_cog :face font-lock-variable-name-face) ;; Variable
     (fa_cube :face font-lock-constant-face) ;; Feature
     (md_color_lens :face font-lock-doc-face))) ;; Face

(setq company-box-icons-yasnippet 'fa_bookmark)

(setq company-box-icons-lsp
      '((1 . fa_text_height) ;; Text
        (2 . (fa_tags :face font-lock-function-name-face)) ;; Method
        (3 . (fa_tag :face font-lock-function-name-face)) ;; Function
        (4 . (fa_tag :face font-lock-function-name-face)) ;; Constructor
        (5 . (fa_cog :foreground "#FF9800")) ;; Field
        (6 . (fa_cog :foreground "#FF9800")) ;; Variable
        (7 . (fa_cube :foreground "#7C4DFF")) ;; Class
        (8 . (fa_cube :foreground "#7C4DFF")) ;; Interface
        (9 . (fa_cube :foreground "#7C4DFF")) ;; Module
        (10 . (fa_cog :foreground "#FF9800")) ;; Property
        (11 . md_settings_system_daydream) ;; Unit
        (12 . (fa_cog :foreground "#FF9800")) ;; Value
        (13 . (md_storage :face font-lock-type-face)) ;; Enum
        (14 . (md_closed_caption :foreground "#009688")) ;; Keyword
        (15 . md_closed_caption) ;; Snippet
        (16 . (md_color_lens :face font-lock-doc-face)) ;; Color
        (17 . fa_file_text_o) ;; File
        (18 . md_refresh) ;; Reference
        (19 . fa_folder_open) ;; Folder
        (20 . (md_closed_caption :foreground "#009688")) ;; EnumMember
        (21 . (fa_square :face font-lock-constant-face)) ;; Constant
        (22 . (fa_cube :face font-lock-type-face)) ;; Struct
        (23 . fa_calendar) ;; Event
        (24 . fa_square_o) ;; Operator
        (25 . fa_arrows)) ;; TypeParameter
      )