Icon 1:
1. In the Layers window, click the duplicate button (next to the down arrow and the anchor). Set to Screen, using the drop-down box in Layers, above where it shows your layers. (Text next to it is Mode) In the image window, go to Images>Merge Visible Layers or Images>Flatten Image. Both work.
2. Duplicate layer, again. Set to Hard Light.
Icon 2:
1. Create a new layer. Click the white paper button next to the up arrow in the Layers window. Choose transparency.
2. Go to the colour box, and change the colour to [HASHTAG]#2a314f[/HASHTAG]. Click the paint bucket and fill the layer (click the icon). Set it to Difference. (Closest you can get by my count, but I'll include instructions for a way to attempt to recreate Exclusion at the end of this)
3. Add another new layer and fill with [HASHTAG]#aab7e8[/HASHTAG]. Set to Burn.
4. Merge layers.
5. Duplicate layer. Set to Screen. Merge layers.
Icon 3:
1. Create a new layer and fill with [HASHTAG]#ffffff[/HASHTAG]. Set to Colour. Underneath the drop down box is a slider bar labeled "Opacity." You can adjust the slider or type a number in. Change to the percentage you wish.
Icon 4:
1. Create new layer, fill with [HASHTAG]#ffffff[/HASHTAG]. Set to Colour, keep at 100%.
2. Create new layer, fill with [HASHTAG]#ff0000[/HASHTAG]. Set to Difference and set Opacity at 50%.
3. Merge layers, duplicate layer. Set to Overlay.
Icon 5:
1. Create new layer, fill with [HASHTAG]#ffffff[/HASHTAG]. Set to Colour, keep Opacity at 100%.
2. Create new layer, fill with [HASHTAG]#ff0000[/HASHTAG]. Set to Lighten Only.
3. Merge layers. Duplicate layer, set to Screen.
4. Create new layer, fill with [HASHTAG]#243062[/HASHTAG]. Set to Difference. Merge layers.
Icon 5:
1. Duplicate layer and set to Multiply.
2. Create new layer, fill with [HASHTAG]#347100[/HASHTAG]. Set to Soft Light. Merge layers.
3. Duplicate layer, set to Screen. Repeat. Merge layers.
Optional:
Instructions on how to recreate Exclusion in GIMP:
1. Top Layer: Set to Difference
2. Bottom Layer: Add Layer Mask (Layer>Mask>Add Layer Mask>From grayscale copy of layer)
3. Bottom Layer: Mask to Selection (Layer>Mask>Mask to Selection)
4. Top Layer: Add Layer Mask (Layer>Mask>Add Layer Mask>Selection)
5. Bottom Layer: Delete Layer Mask (Layer>Mask>Delete Layer Mask)