Convert String To Color In SQLSERVER

CREATE FUNCTION dbo.fn_conversion_string_color
(
@in_string VARCHAR(200)
)
RETURNS NVARCHAR(500)
AS
BEGIN
DECLARE @fsetprefix BIT, -- append '0x' to the output
@pbinin VARBINARY(MAX), -- input binary stream
@startoffset INT, -- starting offset  
@cbytesin INT, -- length of input to consider, 0 means total length
@pstrout NVARCHAR(MAX),
@i INT,
@firstnibble INT ,
@secondnibble INT,
@tempint INT,
@hexstring CHAR(16)

SELECT @fsetprefix = 1,
@pbinin = SUBSTRING(HASHBYTES('SHA1', @in_string), 1, 3),
@startoffset = 1,
@cbytesin = 0

-- initialize and validate
IF (@pbinin IS NOT NULL)
BEGIN  
SELECT @i = 0,
@cbytesin = CASE  WHEN (@cbytesin > 0 AND @cbytesin <= DATALENGTH(@pbinin))
 THEN @cbytesin
 ELSE DATALENGTH(@pbinin)
 END,
@pstrout =  CASE  WHEN (@fsetprefix = 1)
 THEN N'0x'
 ELSE N''
 END,
@hexstring = '0123456789abcdef'
 
--the output limit for nvarchar(max) is 2147483648 (2^31) bytes, that is 1073741824 (2^30) unicode characters

IF (
((@cbytesin * 2) + 2 > 1073741824)
OR ((@cbytesin * 2) + 2 < 1)
OR (@cbytesin IS NULL )
)
RETURN NULL
 
IF (
( @startoffset > DATALENGTH(@pbinin) )
OR (@startoffset < 1 )
OR (@startoffset IS NULL )
)
RETURN NULL
 
-- adjust the length to process based on start offset and total length

IF ((DATALENGTH(@pbinin) - @startoffset + 1) < @cbytesin)
SELECT @cbytesin = DATALENGTH(@pbinin) - @startoffset + 1

-- do for each byte
WHILE (@i < @cbytesin)
BEGIN
-- Each byte has two nibbles  which we convert to character
SELECT @tempint = CAST(SUBSTRING(@pbinin, @i + @startoffset, 1) AS INT)
SELECT @firstnibble = @tempint / 16
SELECT @secondnibble = @tempint % 16
 
-- we need to do an explicit cast with substring for proper string conversion.  
SELECT @pstrout = @pstrout +
 CAST(SUBSTRING(@hexstring, (@firstnibble+1), 1) AS NVARCHAR) +
 CAST(SUBSTRING(@hexstring, (@secondnibble+1), 1) AS NVARCHAR)
SELECT @i = @i + 1
END
END
RETURN  '#' + UPPER(RIGHT(@pstrout, 6))
 END