Как получить шестнадцатеричное значение цвета

debug.? Hex$(ВашеЧисло)

Function FormatHexColor(n As Long) As String
Dim i&, j&
FormatHexColor = "#      "
For i = 7 To 2 Step -1
    j = n Mod 16
    Mid(FormatHexColor, i) = Chr$(j + 48 - 7 * (j > 9))
    n = n \ 16
Next
End Function

?formathexcolor(vbwhite)
#FFFFFF
?formathexcolor(vbblack)
#000000
?formathexcolor(vbgreen)
#00FF00

Function FormatHexColor(n As Long) As String
Dim h$
FormatHexColor = "#000000"
h = Hex$(n)
Mid(FormatHexColor, 8 - Len(h)) = h
End Function

Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long
 
Private Sub Command1_Click()
Dim Color As Long
Dim R As Byte, G As Byte, B As Byte
'Color = Picture1.Point(10, 10) ' Средствами VB6
Color = GetPixel(Picture1.hdc, 10, 10) ' Средствами API (если надо скорость)
 
R = Color And &HFF
G = (Color \ 256) And &HFF
B = (Color \ 65536) And &HFF
MsgBox "#" & Hex$(R) & Hex$(G) & Hex$(B)
End Sub

Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long
 
Private Sub Command1_Click()
Form1.BackColor = &H300102 ' ваш цвет формы
Dim Color As Long
Dim R As Byte, G As Byte, B As Byte
Color = Form1.Point(10, 10) ' Средствами VB6
'Color = GetPixel(Form1.hdc, 50, 50) ' Средствами API (если надо скорость)
 
R = Color And &HFF
G = (Color \ 256) And &HFF
B = (Color \ 65536) And &HFF
Rh = IIf(R < 16, "0" & Hex(R), Hex(R))
Gh = IIf(G < 16, "0" & Hex(G), Hex(G))
Bh = IIf(B < 16, "0" & Hex(B), Hex(B))
'
MsgBox "#" & Bh & Gh & Rh
End Sub