This is a twist on the old standard Feather and Fan. Slipped stitches provide the strands that are later picked up to form the sides of the windows.
The afghan can be made with most yarns and appropriate needles for yarn. The example is made with Caron Simply Soft yarn and size 8 (5mm) needles.
Example is a 37 inch square lap blanket, but pattern can be easily modified to make any size.
In the example I used about 7 oz of Black and around 3.5 oz each of Red, Iris, Berry Blue and Limelight.
Any corrections I have discussed in the comments have been incorporated in the pattern.
Slipped stitches – hold yarn in front or back of work as indicated. Slip the indicated number of stitches by inserting needle to the front, as you would to purl. It is very important to leave adequate slack in this trailed yarn before working the next stitches. Accomplish this by fully extending the work in section of dropped stitches.
Picking up trailing yarn strands – on row with stitches indicated pick up the trailing yarn strands by first inserting needle under the trailing strands then through stitch to knit. Pull knit loop through back below the strands. The strands will be behind the completed stitch. Do this for 5 stitches. The strands will be on the wrong side for the length of these five stitches.
The effect of the pattern is most striking when using at least two colors. A primary color forms the frames for the little stained glass pieces. The sections worked in a secondary color can all be worked in a single color, in a repeat of several colors, or even in different colors for each section, perhaps from scrap yarn.
Multiple of 18 plus 5. Change number cast on to change width.
Cast on 167 with primary color.
Rows 1 and 2: Knit.
Row 3: K3, p2, *with yarn in front, slip 13 purlwise, p5* repeat between * to last 5 stitches, p2, k3.
Row4: K5 *with yarn in back, slip 13 purlwise, k5* repeat between * across.
Row 5: Change to secondary color. K3 *(yo, k1) twice, yo, k2tog three times, k1, k2tog three times, (yo, k1) three times* repeat between * across to last 2 stitches, k2.
Row 6: K3, purl across to last three stitches, k3.
Row 7: Knit.
Row 8: Repeat row 6.
Rows 9 and 10: Repeat rows 5 and 6.
Row 11: Change to primary color. *K9, k5 by inserting needle under the two loose strands before into stitch to knit, k4* across to last 5 stitches, k5.
Row 12: Knit.
Rows 13 and 14: Repeat rows 3 and 4.
Repeat rows 5 to 14 until afghan is desired length. On last repeat do not work rows 13 and 14. Cast off while knitting an additional row.