vhdl-highlight-names

vhdl-highlight-names is a variable defined in `vhdl-mode.el'.
Its value is

t

Documentation:
Non-nil means highlight declaration names and construct labels.
The following faces are used:
`font-lock-function-name-face' : names in declarations of units,
subprograms, components, as well as labels of VHDL constructs
`font-lock-type-face' : names in type/nature declarations
`vhdl-font-lock-attribute-face': names in attribute declarations
`font-lock-variable-name-face' : names in declarations of signals,
variables, constants, subprogram parameters, generics, and ports

NOTE: Activate the new setting in a VHDL buffer by re-fontifying it (menu
entry "Fontify Buffer").

You can customize this variable.