Colour of house regularly seen (3)
I believe the answer is:
hue
'colour' is the definition.
(a hue is a colour or complexion)
'house regularly seen' is the wordplay.
'regularly seen' indicates alternate letters.
The alternate letters of 'house' are 'HUE'.
'of' is the link.
(Other definitions for hue that I've seen before include "Tone, shade" , "'Pigment, colour (3)'" , "General outburst of alarm or protest - . . . and cry" , "red or black, say" , "Delicate shade" .)