Bas Relief can be used to create unique Photoshop gradint color blends. The filter is found in the filter gallery and can be used to create super colorful imagery
New document and set the foreground to black and background to white for the initial bas relief effect and gradient, go to the filter menu and then filter gallery and go to the category 'sketch' and then select the bas relief filter. Set the detail 1 and smoothness 15, light (any direction), click OK and there you have a gradient. Not much different from a normal gradient but still a gradient.
To create another design, change the foreground and background color if you wish, go back into the filter gallery and bas relief and change the light direction and click OK and then edit menu and fade and set mode to overlay or difference etc (you will notice some banding but a blur will blur that away) and edit menu and fade
The effect uses the foreground and background colors in the toolbar to generate the blend. The blend can be any set of two colors. You can apply the effect to create many different combinations of gradients using that method.
Another approach is to use layers and then apply the effect to a layer and create a new amazing design. You can repeat this multiple times. The layer can then be blended with multiple different colorful blends in countless ways by just changing the blending mode to difference or darken or exclusion etc
You can do the same with selections and the effect applied to that. You can also use selections to create quadrant blends and half image blends with a stripe design with selections using the rectangular marquee tool.
To create a colorful stripes design, create a thin selection strip using the rectangular marquee and then set the foreground and background and then apply the effect to create the blend . Move the selection using the marquee and place adjacent to the first strip and then change the foreground and background and then apply the effect again and repeat this with different combos of foreground / backgrounds
Use marquee tool and select a circle and copy and paste, set the foreground and background color, layer menu and convert to smart object, apply the effect via the filter gallery as before with a certain light direction. You can combine multiple smart object layers using the generated layers
You can add the effect to custom shapes. Goto the custom shapes tool and then select a shape layer (top left) and then select a shape. Draw the custom shape on the current layer / art board and then go to the layer menu and smart objects and convert to smart object and then go to the filter menu and filter gallery and sketch and bas relief and create the gradient using the current foreground and background colors.
Create a selection for the entire image (select menu and select all) and then go to the select menu and transform selection and width and height and 50% for each. Drag the selection to the top left. Set the foreground and background color and then apply the effect to create a blend in that selection. Go to the rectangular marquee and drag to the top right and change the colors of the foreground and background and apply the effect again. Repeat this with the bottom left and the bottom right
You can save the effect to the actions panel. Go to the actions in the window menu and then click the record (+) at the bottom of the panel and give it a name etc and then apply all the effects etc and stop recording